I’m not convinced that Tablets will replace laptops for some time. Currently the main obstacle is text entry, but improving voice recognition (have you tried the latest version of Dragon? – it’s impressive, but not a keyboard replacement yet) will eventually overcome this. For accurate work (large spreadsheets, or graphics) a stylus will be necessary as well (I love my iPad but it’s no laptop or desktop replacement…yet).
But eventually it will happen. The directness and immediacy of a tablet are the future of computing.