I have just signed up for the early pick developer program Palm inc is having for the developers. I have missed the window a little, since the submission process started about a week ago, but I think with my wast experience with developing for mobile devices and having diverse development platforms (I develop on Mac (OS-X) and (PC) Windows pretty much simultaneously, leaves me pretty good chances to be admitted.
WebOS is supposed to be at least as appealing as Android and iPhone. I personally like much more Android development than the iPhone development, but this is probably due to openness of the Android and the fact that I actually have quite successful application for Android, while iPhone development didn't result in end user product just yet. I am not even mentioning the Blackberry development...
You can submit the application here