It'll want to be better then #1. Halo was a decent game, but its hype was far to great for what it was. It's just a basic first person shooter with a decent story line and some boring levels. I have no idea why this game got so much attention, if it was just released on the PC it would just been another game but for some reason, it got more hype then any game I have ever seen. Maybe it's because it was the first decent game to arive on the Xbox so that's why it sold so good... who knows.
My son is addicted to Halo....we just got the call last night that he can pick up his pre ordered Halo 2 on Nov 9th at 12:01 am. I sure hope that it lives up to his expectations.
In terms of single player Halo 2 was nowhere near too the great gameplay of the original Halo, but Multiplayer and online are another matter. Playing Halo 2 on XBLive is wicked, I'm loving the Dual Wield ability and teaming up on people with a jeep