Someone at some point is going to figure out a way to make a cam that clips onto the Dock connector of the iPad. Remember, there's no "wrong" way to hold the iPad, so such a device (if the iPad is held "upside down") could easily work.
Maybe not tomorrow, but at some point.
And yes, I expect that "the iPad 2" or whatever they'll end up calling it will "inherit" the sort of cam system the iPhone 4 has (at least for front-facing, anyway). But contrary to a lot of people, I don't think that will arrive next April. I think you'll have to wait longer.