Those who do not own a tablet will have their opinion of them. Those who are "geeks" apparently will be convinced Android is better.
Tell me what computer will fit on a music stand of a music keyboard and store every piece of sheet music / chord charts / lyrics / set lists a muso may have and not look stupid. OnSong + iPad becomes the perfect songbook for live stage use.
Have you seen the Alesis StudioDock and AKAI SynthStation 49. These are iPad specific hardware units designed to increase functionality of the iPad for musos. In these two units alone combined with GarageBand for iPad you have a portable studio/synth setup that you couldn't get for that money in the past.
Sometimes I wish people looked past the fact that tablets aren't simply for doing computer stuff and realise that they are used for so many other things that neither a desktop nor laptop nor phone will do.
PS: I have a first generation iPad 16GB Wifi for sale!
(Yes, I am getting an iPad 2)
PPS: Accelerometer being used for touch sensitivity on the software instruments is pure genius and I hadn't seen that used ANYWHERE else. Apple do think about some things others simply do not.