There are a lot of aspects about The Sims 3 that sound interesting as far as gameplay goes. I wish there was a trial version so I could test out the open neighborhood and see what that's like, because that sounds kind of cool. Even though it does make me worry about missing out on too many important moments in the lives of the sims that you care about it.
I won't be getting it though and here are my reasons why:
1. I'm still enjoying playing and creating (particularly stories) with TS2
2. I barely have the free time to play TS2, let alone a new game
3. I don't have the space to add another game (or even another EP) on my harddrive and see #1
4. From the pictures I've seen the TS3 sims look really ugly. (when TS2 came out I downloaded the pre-release version of bodyshop and started recreating my story characters who I was playing in TS and I was so happy with how they turned out. Their looks were so improved and looked more like I pictured them in my mind. Recreating them in TS3 would feel like going backwards.)
Unless the reviews after the game come out are so good that I can't resist, I'll probably pass on TS3. Maybe by the time TS4 or TS5 comes out I'll be ready for a new game and have more time to play it.