assuming things work as on paper:
the AF! actually a bit better than even I had hoped for
(they should make a second grip that takes a new battery that drives super-tele AF motor full speed, to complete the picture, then ;D ;D ;D ;D)
the 3x3 sampled video! (hope it is sharp though, early reports say the old GH2 looks sharper, but I think it is just because all we have seen is re-compressed and/or high ISO footage with strong NR so far)
the 6fps! (although 7fps woulda been nicer since they left it at the same 22MP), but 6fps is def better than 5 for sure and way better than 4
the improves shutter lag and mirror black out times!
the silent shutter mode without using liveview
the outline on the histogram!
the even better image reviewing
the hopefully solid, full 2/3 stop better high iso!
the wide/tele settings for MFA!
the 7D-like movie/stills mode flip switch (I just wish they kept shutter,iso,aperture, etc. settings for movie mode and for still separate, it's really a pain if you try to quickly go from a few stills to a little video and back when lighting conditions are changing, you waste so much time resetting everything, it can be really bad, plus for still during video, the same settings often are really poor for stills; maybe they did fix this???)
(negs: autoiso remarkably still bungled/crippled for no good reason, although the next matter more: the zero ISO 100 DR improvement (this one in particular :'(), no replacement view screens, no 30MP (this one too :'(, between this and the DR not one bit of better for low iso and/or distance work), the not amazing metering that is a bit out of date vs. competition, price a bit high)