Have it...don't regret it
Received mine yesterday morning (was surprised at the early delivery) and although I have issues, I don't regret it.
The first thing I noticed was; it's heavy...very heavy! It failed my first "real world" test this morning. On the train to work, standing up with a coffee in one hand, I was basically impossible to use for any length of time.
In use, screen get's gunked up with finger marks very quickly, so I think one of those special pens will be in order, for any long sessions.
I'm not an Apple head, I don't own a Mac computer (and never will) but so far I am happy with the iPad and think I will use this quite a lot, although mostly with productivity apps--and the F1 app, which looks sweet!
I actually bought an iPad because I have to check that the books from my epubBooks website all look good and need to try out all those other eBook reading applications, so in one sense I had no choice but to buy one.
I'd say if you have plenty of cash and are happy to be an early adopter, go ahead and buy one. Otherwise wait a while, let the weight and the price come down, before buying.