However much I love my iPad, I'm impressed by this first actual demo of the BlackBerry Playbook:
I'm actually pretty impressed / convinced by the "write once / run everywhere" promise of AIR, having experienced it successfully for applications such as Balsamiq Mockups. If the performance is astonishing (and it seems to fall short of this for now), it could well give the iPad a run for its money.
Multitasking on the iPad should be available pretty soon though, let's hope November holds its promises!