So we just applied for my wife's citizenship, not that I am expecting it to be done by the time our holiday rolls around in December, but was wondering if she did get interviewed and approved just before that holiday, would we have to get a rush job on a passport or could she travel out of the country this once on her South African Passport?

I know this is a premature discussion, but just was wondering if anybody had a similar experience. I am fairly confident that the interview will be schedule while we are back in her home country.

She can still travel with her greencard if she hasn't taken the oath yet. When you do the oath, you turn in your greencard. Following that, you will be able to get an expedited passport at one of the handfuls of locations throughout the country - you're lucky, there is one in your neighborhood:

HOUSTON Passport Agency
Mickey Leland Federal Building
1919 Smith Street
4th Floor
Houston, TX 77002-8049
Hours: 8:00 a.m. - 3:30 p.m., local time, M-F, excluding Federal holidays
Automated Appointment Number: 1-877-487-2778

NOTE: Houston Passport Agency serves customers who are traveling within 2 weeks (14 days), or who need foreign visas for travel. An appointment is required.

You will need US passport to re-enter the USA, if approved for US citizenship, green-card will most likely be taken away and invalidated.

Thanks, that is what I figured, now just have to hope the stars allign.