ahmad: I'm pretty sure any standard BT keyboard should work with the TouchPad but I'm meaning the "official" HP BT Keyboard for Touchpad - will that work with other devices or has HP configured it not to?
I don't see why they would configure it not to work on other devices. If it's any good they stand the chance of selling more for use on other devices.
I see the more likely situation (though I do think unlikely) is the Touchpad being set up only to work with the HP BT keyboard. This could happen by default, as I alluded to above, in that there may be software needed on the Touchpad to run a BT keyboard and that soft ware for the Touchpad may only be available from HP for WebOS when you buy their BT keyboard.