I see OSX and iOS continuing to converge to the point where the distinction will become functionally (if not technically) meaningless. We will of course likely continue to have usage-case distinctions (e.g. The OS on the iMac will have an overall UI distinct from the OS on the iPad for example) but it will otherwise "be the same" if you get my meaning. I ponder this often in my blog (see my signature...)
Hardware in the iPad seems to be evolving even faster than I'd originally thought, if the engadget ipad2 rumors prove to be true. A resolution doubled screen (4x pixels) will take a great deal of CPU/gpu horsepower, which in turn will also allow for apps that absolutely blow our minds.
Can't wait!