I ordered the 80 gig. More battery life (big selling point). Brighter screen. More storage for video.
I think I'm going to order one, too. I don't think I'll buy the first G6 models anyway, so I won't be missing anything. But this sounds outstanding - 80 gig?!
Downloaded iTunes 7 last night, some huge improvements. Gapless playback, and the ability to flip through album covers are my favorites so far.