Haven't given it any thought at the moment (and no one has posted the power rankings since the July rankings) But I see a trend toward getting some of the manga MSs out. If Hi-Nu is coming, you can bet Nightingale is in the works. Might be done by Izubuchi instead of Katoki, like Hi-Nu, though. F90 could come as well, but I would see that as a fix to all of F91's problems with polycap-less joints.
I've heard of a 1/100 Akatsuki (NG or MG) rumor, but that's about it. I'll have to think about it more though.
Edit: Oops, forgot to read a thread over at Gundam Evolution. We will hit 100 MGs in 2007. Guess there will be lots of speculation about that one...