As Ayak and others have pointed out, there is no challenge footage this week. It could be because MB does not want to show the "new colors", or who's wearing what colors in the challenges, or it could be that there is no reward challenge this week. Regardless, no challenge footage is suspicious. Given the one hour format of the show, alot has to happen in the first half hour, assuming the second half hour will still be the Immunity Challenge and the Tribal Council.
During the "first 15 minutes" the twist will be revealed and explained. An early merge or tribal swap, may very well replace the RC this week. People will have to relocate, supplies and water will be divided up, etc. Plenty of activity to fill the second 15 minutes of the show. I'd speculate no RC this week, therefore no challenge footage.
I also agree with IceCat, that Samburu's water issues were given alot of attention last week. An early merge would solve the water problem, but not fit the desciption of "every alliance shattered".
Only swapping tribe members could shatter "...every alliance...", and it would have to be more than one tribe member to do it.
A 3 for 3 swap makes the split a fair 50-50. The 3 new members are on an equal footing with the old members(3-3).
At the same time, the water problem can be solved by allowing the 3 departing members of the Boran tribe to take their "half" of the water with them and allows the departing Samburu members to take their "half" of their food with them.
The new tribes will have equal amounts of food, water, and voting power. "Fair" to all involved, except for those whose alliances were "shattered".
The logistics of all this will replace the RC, because everyone will get a reward of food and water anyway!
Krautboy