Haven't touched it or even thought about it since about a month after it came out. I got caught up in my memories of the first game and my hope for the new one but very quickly realized it just wasn't doing it for me. Still I played it nonstop for those first few weeks and then played the auction house game for a few weeks more (making a rather tidy sum of real cash). I should have remembered I grew extremely bored with Diablo 2 within the first month of playing that one too (though I still go back and play the original all the time).
I think regarding game of the year contention it would depend on how they view it in hindsight. A game that burns bright but fades quickly may not be worth talking about for GOTY, the lasting impression was pretty much "yeah, it was good and I played it intensely for a bit but then was totally over it".
Whereas something like Saints Row the Third, which I have not gone back to either is still something I have very positive feelings about and loved.