I'm definitely waiting.
I only ever use my iPad at home, and I just lay it down on a table or other surface (or on a stand I have for it) when I want to read, watch, or play something. I also have just a thin silicone cover on the back, so the weight doesn't bother me in the slightest.
I'm only an occasional gamer, and mostly use it for watching videos, YouTube, checking e-mail, viewing the occasional PDF for work, etc., and the iPad 3 holds up pretty well for these purposes.
What would really have sold me on the Air is more RAM. I would have bought one the first day it came out if it had 2 GB. An engineer friend of mine once told me that you never want to buy a computer outfitted with just enough RAM to get by, unless you're willing to upgrade in a year. I know computers and iPads use memory very differently, but 1 GB is 1 GB. The next iPad upgrade I make will be when I can switch between several different apps (not even memory intensive ones) and the state of those apps will remain exactly the same, no matter how long I let it sit, just like my desktop PC. People are irritated by different things, and having to wait for tabs in my browser to reload irritates me. Pages would reload faster on the Air, sure, but that's not the ideal solution for me.
What else could they add to the Air to make me want one? I would have liked 801.11 ac Wifi. Apple could have been an industry pioneer here if they had included it, but they'll probably end up ceding that honor to Android in the coming months. I also want 32 GB to be the minimum configuration available so I can get a 128 GB or 256 GB iPad for less. It would also be nice to have USB 3.0 speeds from the lightning port, but I realize that's not going to happen anytime soon.
For people like doctors and nurses (I imagine), a lighter, thinner iPad was just what was needed. I, however, wanted bigger advances in areas that Apple apparently didn't prioritize.
However, thanks to their craftsmanship, my iPad 3 will hold out until these features are available in a future model.