I use iTunes Match and have quite a bit of music on my computer and my phone, so it doesn't often occur to me to listen on my iPad. However, when I do, I exclusively stream, so this might actually be the perfect fit for me. Will let you know when I try it out.
Also please let me know how long it takes to open when you load.... We have an issue with large library parse times... If you get a blank screen for more than a few seconds please time it and let me know how long it takes. We need to put this initial loading/library prep into a new thread.
Well, part of it was selfishness. We wanted to make a visualizer and the iPhone is not a good platform for that.
Secondly, I had experience with XCode and OpenGL and Cocoa.
As a bonus, we figured that there were more iOS tablets and less piracy, but we could be wrong on that one. :)