This absolutely ROCKS, and I can't wait to hear what it sounds like with vocals! I'm not big on the panning of the lead guitar -- it's a little distracting to me -- but that's the only thing I'd change. I'd just leave it where you have it: mostly in the right channel. I do like when you pan it center to left at the start of the outro, however. The mix is superior.
As always, I have to ask: What's the rig you used for this (i.e., instruments, effects, software and recording gear)?
- Keith