Jon, here’s your “FY” back at you.
Didn’t see it coming. But admit it, Trish has been such a non-entity that any move on her part would have been a surprise. I’d have bet that Shawn was the one to go. (But not a seawater and blood clam smoothie. You might want a chaser on that, Skammer.)
Biggirl, here’s the way it works. At some point, usually but not always when they get down to ten players, the tribes merge into one tribe. The show makes a big deal out of it; new name, new bandanas, new flag, etc. But the big factor is that all challenges are individual from that point on. Only one player will win the reward (although often he or she will be given the chance to share it with one other player). And only one player will have immunity and be safe from being voted off. Everyone will go to Tribal Council and vote (including the immune player). Because of this, players like Rupert, who were valuable because they won challenges for their tribe, are now vulnerable because of their ability to win challenges for themselves.
It’s looking like we’ll have a 5-5 merge. Past practice has been that each tribe has tried to convince a player from the other tribe to switch over but this rarely happens. This year, with Jon so vulnerable now, it might. (Of course, being a dick during the looting didn’t help Mr Fairplay.) More often what happens is the two tribes expect there to be a tie in the first post-merger TC and try to guess which player is the most vulnerable to a tie-breaker.