I think it depends on what happens next week. If Mark & Michael somehow catch up (and really, it does seem possible, given they were spotted in an airport at night, and the tasks of the next leg seem to take place during the day -- there's time to meet up at a connection). If, by some strange occurrence, Jaime & Cara end up eliminated instead, then it's clearly Margie & Luke going out in fourth (can't see it being anyone else, as both teams were spotted together). If Mark & Michael are, indeed, screwed by the big time gap between them and the other teams, however, then yeah, Margie & Luke and Jaime & Cara are at least in the F3, with Kisha & Jen and Tammy & Victor fighting it out for that last spot.
Frankly, I hope it's the latter scenario, as Tammy & Victor being in the F3 with Kisha & Jen and Mark & Michael would be WAY too much of an anticlimax. Even more of one than last season's F3. If it is the latter scenario, then I think it'll go like this:
1st: Margie & Luke/Kisha & Jen
2nd: Kisha & Jen/Margie & Luke
3rd: Jaime & Cara
. . . With Jaime & Cara in third possibly (and this is only speculation) because Jaime's taxicab driver treatment karma comes back to bite her sometime on the final leg, and one driver refuses service to her and Cara. Margie & Luke and Kisha & Jen, based on the upcoming scuffle and subsequent feud, fight it out for the top two spots instead.