Cool!
I've been using my 32Gb iPad for a lot of serious music work - scetches, some of the synths, loop creation etc - since I bought it in June last year. It's great because I can go anywhere to get some inspiration to take back to the studio.
I plug whatever I can into the Camera connection kit and I have the iRig Keys which is pretty cool. It mainly sits on my DAW as a tiny controller at hand but works wonders with the iPad.
An associate of mine whom I do a lot of shows and writing with just
ordered this to take out with the iPad and his mics, as well as using it for his simple Ableton Live setup. It's cheap, has two ins, MIDI I/O and works without drivers. We'll see if it's any good soon
Now we're looking to utilize these gadgets Live as well.
The mobile "revolution" certainly has it's perks and definitely is a lot of fun! I will never use an iPad as a serious DAW but as a tool in producing music, and as a cheap synthesiser for live playing, it really is excellent