In my opinion, if apple releases another iPad at the end of the year, it would be a bad thing. The reason why is because they are launching one now, and people are going to buy it. If they release a new one those people will get pissed and it could hurt apple's reputation.
They make and release products on a yearly basis. I think they should keep it that way. I know if I spend $700 on a iPad 2, then and they come out with the iPad 3 in a few months then, I'll be pissed. It would definitely make me consider investing in apple in the future.