I can't make a case to myself for upgrading when I'll want the higher resolution display, which right now seems very likely to hit next year in the iPad 3. I don't want to fork over $700 this year AND next year. I might change my mind in the next few months if our teen daughter gets her internet hours down to something reasonable without our constant monitoring. Then I'd get an iPad 2, my daughter and my wife would share my original iPad -- my wife sort of wants one, but not enough to spend the money on it. That would make paying for a high-res iPad 3 more tolerable: I get the 3, my wife gets the iPad 2, our daughter becomes exclusive owner of the original iPad.
Or work picks up and I have lots of spare cash and I get an iPad 2 just because it then becomes a trivial expense. As of now, though, no iPad 2.