My standpoint on the new game is this, it'll all depend on many factors as to if I or a number of like minded people I've read will ever get TS3:
1. The Look - As Odessa pointed out, the game doesn't look that visually appealing. The Sims themselves have a very odd look to them, and the skin complexion looks as she so eloquently put it "Doughy". Skinning is pretty much going to be a mandatory CC requirement if you even want to make anything close to what you have on TS2.
2. Content - Speaking of skins, CC in general is going to be a major issue. It'll more then likely take a good year or so before any good CC is available, let alone from some of the "famed" content creators out there. And who's to say any of them will rush out to get the new game immediately either? Most of the Maxis default stuff is trash, so chances are we will see a lot of recolors to start, but as far as meshes go, or new body types...I wouldn't hold my breath.
3. Longevity - There are people who (like me) have invested YEARS on the TS2. While I'm new to this board, I've played the game for 4 years now. I have generations of sims in double digits now. Neighborhoods that have all kinds of history behind them. There's no way I myself can pack all of that game time in and start all over. It wouldn't even be worth it. Now there are some people who are like me in that regard, and some people that aren't. But for the majority, they've put to much into the game to start from scratch on a new one.
In summary, I'm not at all saying I'll never get the game. I am saying it'll be a good, long time before I do. I'm still quite content with TS2, and there will still be a strong surplus of CC well into and after the release of TS3. Just like it took a few years for the 2nd game to pick up steam, so to will it take years for the 3rd one. For anyone new to the series, yes...it's a definite good idea to get the new game. If you're a casual simmer, good purchase. But if you're die-hard about it and want to be able to customize things to your liking, do yourself the solid of waiting it out. Unless Maxis opens the doors up to creating different body shapes via in game sliders (Like any OTHER game that allows you to create an avatar...let's get with the program, Maxis) don't expect any varied content to emerge on the 3rd game for a while. That's my 2 cents.