I kinda feel like that when I played Starcraft 2.
Man I had such high hopes for it, being a SC1 and Blizzard nerd, I thought SC2 could evoke the same excitement and feeling I had when I first played SC1.
But I was wrong.
Sure it was a nice game, but completely forgetable and I don't even care for Battlenet.
There you go, guess Diablo 3 will be the same "letdown".