Good game, not enough of a step forward from Halo 3 and has been surpassed by superior FPS games.
As for the multiplayer I don't feel that the addition of power ups has changed the core gameplay enough. Couple that with the bias towards Spartans both with guns and vehicles and you have what feels like a imbalanced weak experience. I feel like im playing Halo 3 again and to be honest I was hoping for more. The levels are awful, there are no levels that I really like as much as say Construct or Epitaph. I will be waiting it out for Black Ops for what im sure will be a vastly superior multiplayer experience.
All in all Halo: Reach is a worthwhile experience but one that I will not remember for the good qualities. I find myself thinking about how let down I was by the multiplayer because lets face it, that is a huge part of the Halo appeal and it has drastically fallen down in this area.