VERY excited to get the game.
For me the reasons I played SP vs bnet for D2 don't apply when you look at D3. D2 was a duping mess, Blizzard have learned with WoW how to control things. My internet connection is so much better in terms of speed and reliability. The game has been designed so even with lag you won't notice it. PvP is completely excluded from PVE/coop. You can play with friends only, or just yourself (i'm doing first playthrough completely solo).
I also spent a few years in Guildwars so I'm used to playing a game you can only play online, having limited character slots, limited space.
There are new features in D3 we didn't have in D2 that I'm looking foward to such as the achievements, most people forget there is a gold based auction house.
The game is still Diablo at heart, I'm looking forward to mastering the 5 classes, hunting all the loot etc. Just need to work with the constraints eg screenshots/google documents to keep track of items found. I mean you can collect 100 isenharts cases in d2, who uses them. We got really lucky with ATMA and the other programs.
I'm buying a collectors edition
I'm taking 3 days off work
I'm really excited
I'm still going to continue my outstanding D2 projects
I'm also getting Torchlight 2 and looking forward to the coop there.