I wasn't a huge fan of Halo 2's campaign, it was a little...repetitive, the multiplayer was quite fun, despite some rather sucky weapon balance and hit or miss close quarters combat. From what I played of the beta, both of these issuses seem to be gone (the former at least) and its a lot more fun because of it.
I'm also looking foward to the higher level of customization in multiplayer (Cueball and I had many a good time involving Speed X 300% and Zero gravity :P), the armor customization thing looks cool, but its not something I'm immensely interested in. Forge certainly looks interesting (for those who don't know, its basically a Garry's mod esque item placement/editor that allows you to mess with spawn points/objects/other players in realtime, you can switch out of the editor and into normal gameplay in realtime as you wish), should finally make Halo-Kart a reality :P.
Hopefully, The single player campaign is all its hyped up to be, as Bungie have been pimping the hell out of the scale and depth of it (with most journalists testifying). If the scale and scope of the game is as big Bungie would like us to belive (they have stated that online Co-op is a challenge to include as players may be two or three miles apart at any given time) then we could be in for something good, we'll just have to wait and see.
