It has to be done sooner or later. A company has released a notation program for the iPad.

http://www.symphonypro.net/

Gabe,

I've been wondering if Sibelius or Finale was going to do something like this for a while now...

I don't understand why they haven't either because the code from both of their current Mac Binaries in Objective-C is easily translatable to the iPad platform, they would just need to tweak the touch interface and scale the view space. 

It probably has to do with the fact that they're stretched thin as it is, at least at Sibelius. They're really not that large of a company, so they do well to put out the products they do now in a timely fashion.

The reviews on iTunes are pretty interesting...

http://www.sibelius.com/products/avid_scorch/index.html

Yeah dude, this Avid Scorch app is pretty sweet. Can't write the music with it, but it works great with sib files already in Dropbox. I'll be trying it out in a private lesson setting over the summer, and with mirroring to my projector in the fall.