eddie, a friend is very close to pulling the trigger on the Akai Synthstation 49 controller keyboard designed for the iPad.

http://www.akaipro.com/synthstation49

I'll let you know if he goes ahead with it and what his thoughts are.

As for the iodock, there's 3 pages of rather unrestrained user comments at KVRaudio: http://www.kvraudio.com/forum/viewtopic.php?t=324432&postdays=0&postorder=asc&start=0 with links to reviews elsewhere.

If I had an iPad, I'd be saving up for way too much kit for the thing. I do believe we are at the nexus of another wave of landslide change in the music making world with the ipad and iphone interfaces. At the apple store, the iRig for Amplitube is $39. That is simply too cool.