The highly predictable "annual release cycle" actually hurts Apple in the marketplace.
It causes too long of a "blackout" period where people are hesitant to buy because a new model is just 2-3 months away...
If they did updates more like other products (iMacs, Macbook Airs, etc.) then that blackout period would only be a few weeks long.
The annual release cycle also hinders Apple from making small incremental improvements - like slight speed bumps etc. These incremental improvements have let companies like Samsung get buzz several times a year as slightly improved models of the same basic device get released.
I think it's highly probably that Apple will be releasing incremental updates to iPad hardware. It's not like a phone that comes with a 2 year contract -- so it's to their advantage to do so.
Those incremental improvements are going to directly affect one of Apple's biggest strength, cheaper parts due to the huge quantity that they ordered. It is also going to directly affect margins. This is why Apple has been enjoying huge margins with relatively small marketshare.