I was incredibly hyped for D3 but after playing the beta...
I played the beta w/ all 5 characters to completion lvling 3/5 to 13 but I found the game strikingly similar to Torchlight (which was developed by the original team of D2)
The system of building ur "mana/rage/watever" to use ur more powerful spells is incredibly annoying, but I'm hoping that end game ur gear will help with regen so you won't have to and you can just spam spells.
I'm probably still going to buy it but I'm just a bit disappointed in the combat, however that may change end game which is what rly matters anyway. I think the only reason why Diablo 2 was as long lasting and addictive as it was, was due to its economy. Everyone thats ever played has been in it for the items. The gameplay in D2 would get boring rather quickly but the whole pt was to accumulate tons of wealth from trading items.
So main pt, as long as the gameplay is mediocre I'll be happy just farming drops to sell back out on the AH.