I’ll wait from 2nd or 3rd generation of the iPad - I think. That’s what I did with the iPod Touch and the unibody MacBook Pro. Let the first generation customers find all the quirks, let the developers write apps and when the overhauled iPad (with camera please!!!) is released it will probably be a near perfect device.

Another note: the bookshelf thing and the way books are displayed is a 1:1 copy of the iPod touch/iPhone Eucalyptus app, which is great for reading english literature from Project Gutenberg.