The console is a fine console. It's reasonably powerful, reasonably priced, has a good controller, has backwards compatibility, plays multi-plat games competently, has a good operating system, and has a decent lineup of exclusive games.
It's main problem is that there is no excitement for the thing. It's honestly difficult to tell retroactively how well the 360 would have done if the PS3 wasn't moronic, but the simple problem is that the Xbox doesn't have the brand recognition that the PlayStation has. I think a lot of people just feel like PlayStation and Nintendo do their own things, and Xbox is just trying to be a second PlayStation.