You are counting on webOS being nothing more than a WebKit browser. I am sure that's not the case.
I am also sure the iPhone is not the primary target the Pre is aimed at. There is a host of Windows Mobile, RIM and Symbian slightlycleverphones (it takes more than a qwerty keyboard to be a smartphone) that are pretty much in Palm's crosshairs.
And, sorry to say, you sound like an Apple fanboy ;-) I know. I sound like one very frequently.