My question is "what is it".
It does everything a regular computer does except its not nearly as powerful and its not as ergonomic unless you are like sitting down with your knees propping it up. Most people buying computers buy laptops already so an extra $500-$900 for the iPad seems pretty pointless. If you're buying it to read a book, buy the kindle... or just the book.
I guess the thing is that this product isn't really revolutionary in any way. Apple isn't really using any "new" technology that we haven't seen from them already and the eBook reader and tablet PC have been out for ages.
I suppose we have improvements to look forward to.