iPad2 looks better for music production...

[JesC]

Garage band is going to work both iPads.

[Sambo]

It's good if you like jotting down music when you're on the go. Sometimes you get beats and rhythms in your head, then just can't remember them when you get home, which is as annoying as finding out you have hep.

[TwistedPanda]

Soundprism is releasing a new version with CoreMIDI support. That interface is going to change everything. So freaking cool.

http://audanika.com/

It will work a-ok on both iPads.

The only way the iPad 2 will be better is if you're using a DAW on it, but I just can't understand why you'd want to do that except for the novelty factor ala Gorillaz. The device is an awesome controller for normal DAWs though!

[Sambo]

As said before, it makes a fantastic instrument and controller, but it's by no means a full featured DAW. Give it a few years though, and there'll be a rap artist who gets famous just by using his iPad for an album.