Maybe it's my optimistic view of this, but from the beginning, I thought PYL, TPIR, and FF would be the most recognized formats, and thus the 3 episodes that would do the best during GSM's run (thankfully, only one of those 3 has been played so far, and looking at the ratings, I really hope my prediction will come true)...
Thus, IMHO, I immediately think PYL, TPIR and FF should stay. MG and LMaD should stay too, but replace CS with HS, and have all of the ousted celebs up to that point serve as some of the squares, with maybe Peter Marshall or Tom Bergeron as the center square (the celebs have a shot at answering agree/disagree questions correctly, right?). Replace BTC with $25k Pyramid, and whichever 2 teams who win the first 2 rounds faceoff in the final round with their appointed partner. The first 2 Winner's Circles: $10k, the final Winner's Circle: $25k.
Maybe John O'Hurley could do better than Ricki, but that's the only person I can think of on the top of my head that would have a decent chance of doing well. Otherwise, keep Ricki, at least she'd have the first run of the series behind her belt...
Burton Richardson would be a good announcer, and you could theoretically have true contestants on the show instead of celebrities. It could be advertised as the ultimate test of contestants' true, all-encompassing, game show skill...
Seriously though, with the ratings not being the greatest, I don't see it coming back unless these next few shows blow our minds away...