Since we see the tribes getting the keys to the lock boxes, then running around frantically, then the two tribes rowing (in the web promo) in the same clothes and their yellow and blue buffs. Later, we see lots of shots of everyone in red buffs, giving confessionals in new locations (Dave), and what appears to be an individual challenge featuring people in red buffs standing on red-painted props. So we'll guess that Wezzie's pre-game spoiler that the contestants spent the last 20 days at a different location (the Forest of Life), suggesting all the contestants live together at one camp, has been proven correct. Presumably, the boxes contain directions to the new camp. The running around Jaburu is shown doing is probably because they have a limited amount of time to get their stuff, as with the switch. Taking into account the need for prior footage of Alex moping about Shawna's departure, the construction of a new camp, and time to highlight everyone's anger at Roger's bossiness, there probably won't be room for an RC in this episode. Besides, it looks like there is food at the IC.

But is it really a merge? Well, that's the relevant question. The previews make no mention of such a thing. Whether that camp involves one or two tribes remains an open question. There is also the matter of the next episode's title, "Sleeping with the Enemy," which has been recycled from the first post-fake-merge episode of S5. It's unlikely CBS simply colored the buffs red, because (1) they did a good job of it, even in action sequences, and (2) they also had the foresight to put red seats on the stools for the IC. This sort of attention to detail is not characteristic of CBS's false-color efforts, so we suspect they really are wearing red buffs.

So that leaves three options: (1) a real merge; (2) a fake merge, leaving the tribes as they stood in Ep6, or (3) as Seftor at votedoff.tv speculates, a fake merge with the men and women switched back to their original tribes. At this point, we bring up a Jeff Probst quote in a ugo.com interview, "...in Thailand, we did the fake merge. Now the Survivors that were shooting the Amazon did not know that.... But we do have to consider that our audience has already seen it, so if we do it again, we have to know that, for them, this is old news, and make sure that, if we do it again, we spin it slightly in a way that is different for them, as well as for the survivors." So it seems possible the red buffs could be the bait to fool the cast and audience.

To rule out some of the options:
(2) Fake merge with tribes still in twisted (mixed-gender) configurations. Heidi and Jenna are shown together in what appears to be a joint confessional, and collaborate in the stripping during the IC. This seems unlikely, since if it was a fake merge, they would have been told prior to the IC.
(3) Fake merge with contestants switched back to original tribes. Since the original tribes were gender-specific, this would be much more simple for the average viewer to keep track of, if everyone is wearing the same color buffs. But as TsMom points out in Seftor's thread at VO (link above), the original tribes are uneven (6-4), so the men would have to have been sitting two people out during the IC. So this, while it would have been an interesting twist, also seems unlikely.

That leaves a standard, 10-person merge as the most likely possibility. slimmyworm revealed several weeks ago that "During an E7 challenge, what appears to be the RC, Heidi is going to do something that likely involves nudity in some way, in an attempt to win the challenge and the food reward that comes with it." Perhaps the "surprise" here is that an IC win comes with food this episode. Or that Heidi and Jenna get naked (big surprise there).