Recent seasons have concerned themselves less with pushing the players' physical boundaries while living in the wild, and more with setting strategic hurdles; reward challenges center around food as often as they used to, but the contestants don't seem desperately hungry, as they did in the past, but rather merely bored with an all-coconut diet....The other route I'd consider are themed seasons: an all armed forces season, lawyers v. doctors, an international season with English speakers from twenty different countries, an all-college student edition, all female season -- something that's about "how is this group of people going to interact in the jungle?" rather than just the pure strategery. They've ramped up the new strategic elements as far as they can go, and it's time to step back.
The "Survivor" premise still has plenty of life left in it, but between the goofy extra gameplay elements and the favoritism shown to various non-winners, it seems like the producers don't trust that premise to yield good television. Going back to basics -- dropping the contestants in the middle of nowhere with a canteen and their conversational skills -- is the best way to get the show back on track. And now that it's gone back to the all-stars well three times, it's probably the only way left.
added: This may as well be our omnibus Survivor catch-all post; Dan's interview of Colby is posted, revealing a strategic side the producers didn't show us ("I really had convinced everyone of this sort of apathetic player who could just take it or leave it. It was part of my strategy and it worked,") with more to come, and anyone with further thoughts on any aspect of the show can place them here.