^5 Andy!
I think XBL will get a major overhall before the years out, with several big additions. Stuff that will allow you to make full use of the larger HDD they will be releasing...
Halo 3 will almost certainly be announced at E3, and i think they' ve been officially avoiding it because they need it to have a big enough impact. E3 this year is pretty much all about Revolution and PS3, so Microsoft will obviously be bringing one or two big guns to the show, if only to prove they won' t be dominated.
I think we' ll see more of Too Human, Dark Sector, Lost Odyssey, Blue Dragon, WarDevil, Sonic, Lost Planet, Mass Effect etc... for 360, and a few big name titles announced exclusively for 360 too.
I' m looking and hoping that Live Arcade gets flooded with a lot more games, ...specifically some SNK stuff, maybe even stuff like Sega Saturn and Dreamcast games (although SEGA have already said some of their retro games will likely be available for Revolutions Virtual Console).
The Xbox Live Dreamcast stuff i' ve heard from several people and is something i find very interesting, especially given that PS3 will be able to download games and PSP will be getting PSone games playable form the memory stick. It' d be a nice little earner for SEGA too!