I put it down as the same as computers: Get what you want now. If you wait for the next best thing, you will always be waiting.
They will update the iPad yearly, so why not get one and enjoy it?
Faster processor? huh..it's pretty fast now and I'm sure it'll get faster ones but I am fine with the speed now.
Better cameras? Well, all I use mine for is Facetime and the resolution is just fine. Who would ever take pictures/video with an iPad? Too bulky for that. That's what the iPhone is for.
The only way I would like it improved is to give it a retina display. High rez pictures on an iPad with that would be stellar!
I echo John's sentiment about the cameras too. In the two months I've had my iPad 2, I've taken maybe two pictures, tops. The pictures in question were pretty disgraceful, now that I think about it (Apple should be ashamed to put such awful cameras in what has become a flagship product), but at the end of the day, I can't see cameras becoming a serious issue for the folks that bring us updates.
Yeah, retina display would be nice, but man, it's pretty nice right now. Kinda like you aren't missing anything until it's updated, then you are like whoa! of course! heh