I would so love to see some real research numbers on tablet weight and arm fatigue.
RIM is right it, weighs less, but I think once you cross a certain threshold it doesn't matter, lite is lite enough, and I think iPad2 does/did this.
My arm would notice my v1 iPad after a bit, not at all with my v2.
So then you just have their claims to portability but it doesn't really fit in a pocket, etc.
So given that you just look at the screen and battery life and the choice is obvious.
If they fix the apps issues and make a 10" one, a year from now could be interesting.
With ipad2, TouchPad, and a 10" PB.... not sure why the avg user would choose an android tablet.
The target audience / avg user of a tablet wants total ease and integration, not the erector set geek it out that comes with the android tabs, IMO.