Ok, I agree with the logic you all gave - it makes perfect sense that the sent date is probably the most accurate measure.
I also took the suggestion to use the "last seen" time for inactive profiles. If the I-129F sent date is at least 90 days ago, and it has been at least 60 days since they logged in, I now consider this profile inactive. These code changes were pretty small to make, but I could easily have messed something up in a new and exciting way... so reader beware.

Also, not all timelines have associated profiles, and some profiles mark their "last seen" time as private, so there are some that can't be evaluated this way.
So here is the list with these alterations.
Can you tell I miss my girl?

CODE
Pending VSC K1 Applications
From: 4/30/2007 To: 1/28/2008 11:50 PM CST
# Name I-129F Date Sent Days Since Last Seen (if older)
1 Brady & Hannah 05-05-2007 0
2 Manuel & Lani 05-09-2007 (Has RFE) 0
3 Elena & David 05-11-2007 0
4 Lalina & Ramesh 05-14-2007 (Has RFE)
5 Dayfenix & Eric 05-19-2007 (Has RFE) 46
6 Oscar & Lora 05-26-2007 (Has RFE) 1
May has 6 of 66 pending (90.9% complete), with 1 NOA2s in the last 30 days, and 2 inactive profiles.
7 GA & ER 06-01-2007 0
8 Selena & sterling 06-01-2007 1
9 Ana & Virgil 06-04-2007 0
10 Harlene & Glenn 06-04-2007
11 Peter & Erica 06-05-2007 0
12 Hanako & Andrew 06-08-2007 0
13 I & W 06-26-2007 41
14 wala & jayel 06-28-2007 7
June has 8 of 74 pending (89.2% complete), with 1 NOA2s in the last 30 days, and 3 inactive profiles.
15 Sunflower & Rino 07-01-2007 13
16 A & E 07-02-2007 13
17 Mohammed & Melinda 07-13-2007
18 maryna & matt 07-17-2007 3
19 Mohammed & Melinda 07-17-2007 0
20 Lusi & Gabriel 07-19-2007
21 Marvin & Tonza 07-19-2007 0
22 Matthew & Marisa 07-20-2007 11
23 David M Corrigan & Rebecca J Perfetti 07-23-2007
24 H�l�ne & Stephen 07-23-2007 52
25 Abdelmounim & Donna 07-24-2007 44
26 Luisa & Robert 07-25-2007 53
27 *** & *** 07-26-2007 (Has RFE) 0
28 Carmen & Bert 07-27-2007 10
29 Maribeth & Earl 07-28-2007 (Has RFE) 6
30 Nohemi & Jorge 07-28-2007 (Has RFE) 1
July has 16 of 128 pending (87.5% complete), with 17 NOA2s in the last 30 days, and 9 inactive profiles.
31 Shobana & Sunil 08-15-2007
32 Arlene & Steve 08-17-2007 4
33 Kheng & Ken 08-20-2007
34 anca & val 08-24-2007
35 Golda & Sean 08-24-2007 (Has RFE) 19
36 Loshiel D. Benlot & Kenneth C. Bose 08-25-2007
37 Supanna & Wasan 08-27-2007 0
August has 7 of 38 pending (81.6% complete), with 8 NOA2s in the last 30 days, and 3 inactive profiles.
38 shea & all 09-01-2007 0
39 Jo & David 09-09-2007 0
40 Sharda & Neil 09-10-2007 0
41 Anil & Cindy 09-14-2007 (Has RFE) 0
42 Bryna & Greg 09-20-2007 7
43 Victoria & Philip 09-20-2007 (Has RFE) 0
44 Magda & James 09-24-2007 0
45 rebecca & dominick 09-25-2007 13
46 Rebecca & Dominick 09-25-2007 0
47 Elnara & Mike 09-29-2007 0
48 OS & ST 09-29-2007 4
49 Palm & Christian 09-29-2007 0
September has 12 of 58 pending (79.3% complete), with 35 NOA2s in the last 30 days, and 1 inactive profiles.
50 Alla & John 10-01-2007 11
51 Guiying Liu & Alvin Michael Smith 10-01-2007
52 Michael & Elizabeth 10-01-2007 0
53 Sofie & Fabien 10-02-2007 0
54 Lola L. & Alvin E.B. 10-03-2007 0
55 Aron & Emily 10-04-2007 0
56 david & tonisha 10-05-2007 1
57 Nomie & stuart 10-05-2007 0
58 Kevin & Angela 10-06-2007 0
59 Philip & Kirstin 10-08-2007 0
60 Eliane & Daniel 10-09-2007 (Has RFE) 6
61 Sweety & Baby 10-11-2007 0
62 Anna & Denny 10-12-2007
63 Goodness & Hydro 10-12-2007 3
64 emir & kailee 10-15-2007 39
65 Emma & Sammy 10-15-2007 1
66 Hau & Keith 10-15-2007 0
67 Mary & Dan 10-15-2007 3
68 karol & cesar 10-16-2007 1
69 Victoria & Ryan 10-16-2007
70 Doina & John 10-17-2007 0
71 Fiona & Phillip 10-17-2007 4
72 Oral & Marcia 10-18-2007 1
73 Theo & Antionette 10-18-2007 0
74 Yulia & Larry 10-18-2007 5
75 Alena & Harry 10-19-2007 0
76 K & W 10-19-2007 0
77 parveen & ayan 10-19-2007
78 Nelyn & Scott 10-20-2007 2
79 cheryl & lee 10-22-2007 0
80 Jane & Paul 10-22-2007 24
81 Lyndilo & Nate 10-22-2007 0
82 Mark-Edward & Kristin 10-22-2007 1
83 N & L 10-22-2007 2
84 Campbell & Halle 10-23-2007 2
85 Elli & Chris 10-23-2007 0
86 Flavia & Frankie 10-23-2007 6
87 Xian & Jaime 10-23-2007 3
88 Camille & Scott 10-26-2007 6
89 Graeme & Megan 10-27-2007 6
90 Liudmila & Dennis 10-29-2007 (Has RFE) 5
91 Santiago & Farrah 10-29-2007 (Has RFE) 0
92 Adriana & Rex 10-30-2007 32
93 Sandra & Greg 10-30-2007 22
94 Joanna & Stephen 10-31-2007
95 Stephen & Roxanne 10-31-2007
October has 46 of 73 pending (37% complete), with 23 NOA2s in the last 30 days, and 2 inactive profiles.
96 Andrea & Alex 11-01-2007
97 Jamie & Lauren 11-01-2007
98 Sasha & Eriq 11-01-2007
99 Toni & Matt 11-01-2007
100 Chahid & Stacy 11-03-2007
101 Anne & Keith 11-04-2007
102 Rupa & LT 11-06-2007
103 Eva & John 11-07-2007
104 K & S 11-07-2007
105 philip & nicole 11-07-2007
106 Tati & Charlie 11-07-2007
107 L & C 11-09-2007
108 sophia & john 11-09-2007
109 Lee & Sebastian 11-10-2007
110 Liliana & Noel 11-10-2007
111 Yao & Liwen 11-10-2007
112 Andres & Elizabeth 11-13-2007
113 Michal & Caitlin 11-15-2007
114 Natalie & Ryan 11-15-2007
115 Eunice & Wesley 11-16-2007 (Has RFE)
116 John & Pamela 11-16-2007
117 Nina & Scott 11-16-2007
118 Okey & Renita 11-16-2007
119 Craig & Mindi 11-17-2007
120 Nicoleta & Shawn 11-19-2007
121 Yui & Tj 11-22-2007
122 Elias & Samantha 11-26-2007
123 Tatiana & Tom 11-26-2007
124 Jackson & Melissa 11-27-2007
125 Rrez & Chris 11-27-2007
126 Daniel & Andrea 11-28-2007
127 Lindy & Keith 11-29-2007
128 Elena & Mike 11-30-2007
129 Hayden & Joyce 11-30-2007
130 Yazmin & Kevin 11-30-2007
November has 35 of 36 pending (2.8% complete), with 0 NOA2s in the last 30 days, and 0 inactive profiles.
131 Damar & Douglas 12-01-2007
132 Graeme & Jen 12-03-2007
133 Thunchanok & Robert 12-04-2007
134 Yanilda & Donald 12-04-2007
135 Benni & Patti 12-05-2007
136 Laura & Nicholas 12-05-2007
137 Franziska & Ron 12-06-2007
138 Stephanie & Stephen 12-07-2007
139 Jamaica Eva Ragas & Timothy Dulin 12-10-2007
140 Bonnie & Timothy 12-11-2007
141 Hiu Ha Chan & Tanffy Chan 12-12-2007
142 sweet_face & pooh_bear 12-12-2007
143 Gem & Frank 12-13-2007
144 Habibi & Habiba 12-13-2007
145 David & Marcela 12-14-2007
146 Kat & JD 12-14-2007
147 Svenja & Aaron 12-17-2007
148 Lu & Tom 12-18-2007
149 Helena & Paul 12-19-2007
150 David & Shannon 12-20-2007
151 Liliana & JCardenas 12-21-2007
152 Lori & Eric 12-21-2007
153 Suchada & Alvin 12-26-2007
154 alena & tj 12-27-2007
155 dawn & marvin 12-27-2007
156 Shiyang & Anthony 12-27-2007
157 Amy & David 12-29-2007
158 maribeth & randy 12-29-2007
December has 28 of 30 pending (6.7% complete), with 1 NOA2s in the last 30 days, and 0 inactive profiles.
159 E & L 01-01-2008
160 jomylyn & michael 01-04-2008
161 Marco & Nicole 01-04-2008
162 Mina & Fred 01-04-2008
163 Santos & Donna 01-04-2008
164 Gosia & Brian 01-05-2008
165 L & T 01-07-2008
166 Lilliput/Rosehall & Trelawny 01-07-2008
167 Lucia & Tom 01-07-2008
168 Azzeddine & Kathleen 01-08-2008
169 Alba Lucia Perez Vasquez & James Claydon 01-09-2008
170 Gerry & Karen 01-10-2008
171 Louis & Catherine 01-11-2008
172 Femi & Noel 01-12-2008
173 Priscilla & Eric 01-12-2008
174 TL & LN 01-12-2008
175 Justyna & Dominik 01-14-2008
176 Miriam & Simon 01-16-2008
177 Alejandro & Wanda 01-17-2008
178 Tim & Schmissa 01-17-2008
179 Bella & Joe 01-19-2008
January has 21 of 22 pending (4.5% complete), with 1 NOA2s in the last 30 days, and 0 inactive profiles.
There are 179 pending of 543 applications (67.03% complete). 7 duplicates and 21 INACTIVE profiles ignored.
Profiles are considered inactive if the I-129F sent date is at least 90 days old, and the user's last seen time is 60 days ago or more.
NOA2s issued in the last 30 days:
Jan 28: 1
Jan 27: 0
Jan 26: 0
Jan 25: 3
Jan 24: 6
Jan 23: 2
Jan 22: 5
Jan 21: 0
Jan 20: 0
Jan 19: 0
Jan 18: 7
Jan 17: 3
Jan 16: 3
Jan 15: 4
Jan 14: 4
Jan 13: 3
Jan 12: 2
Jan 11: 4
Jan 10: 4
Jan 09: 5
Jan 08: 6
Jan 07: 9
Jan 06: 1
Jan 05: 0
Jan 04: 4
Jan 03: 2
Jan 02: 6
Jan 01: 0
Dec 31: 2
Dec 30: 1
87 total NOA2s in the last 30 days.