I do think they'll incorporate some similar controller as the default, providing optional classic controllers much like Nintendo does now.
Ultimately, the few who really, really despise motion controls themselves (as opposed to the people who either hate motion controls because of the way they are being implemented, or the people who just hate Wii for its library, or the pre-existing Nintendo haters) will be no great loss, while Sony and MS have a world to gain.
Hardcore gaming could be a great marriage with motion controls, its not limited to the Wii remote anyway, and its not mutually exclusive. A middle-of-the-road solution could probably be found pretty easily.
If Sony and Microsoft don't wish to try and expand their horizons, that's their business (and it is possible, i suppose. Success does not automatically need to be copied, like someone here said. If the industry was purely copycat, then Wii wouldn't exist in the first place, or if it did, it would at least have DVD functionality)