Halo 2 is probably my least favorite in the entire series. I never really got that grand adventure experience I felt like I had in CE, or even in 3 or Reach to lesser extents. I also didn't really like the Arbiter twist, not because I need Master Chief as the main character, but rather I just thought it was handled poorly, or at least not as well as it could have been. It definitely had its moments, but I just never fell in love with the game like I did with CE, and I never really even got into the multiplayer either.
With that said, I think this could do well. A lot of people would like to return to the game, but with new, upgraded visuals. Hell, maybe I'll play through the single-player again and change my mind on it.
I am curious as to how the multi-player will be handled. Obviously it's not going to be its own separate mode, as Bungie, and now likely 343 try as hard as possible to keep their newest main entry in the series as the focus multiplayer wise, so maybe we'll see some Halo 2 maps packed in with use in Halo 4.