I think the game is still very much alive.
I play this game with my wife everyday after work and on weekend. We had a blast at refining our characters.
Beat inferno b4 1.0.4 patch when it was still in the harder difficulty. 1.0.4 is getting easier but I love the fact that my wife can play this game to get loot and sell it in RMAH.
We are not selling by much. Sometimes no sale for whole week but sometimes we can sell more than 30-40USD a week.

I'm doing WW barb run in act3 and 4 the whole time with this build.
https://us.battle.net/d3/en/profile/KFC-6478/hero/14336307

if u guys quit in inferno. I can tell u guys that u all have missed the fun.