You should definately add on to more of this, it's frigging sexy so far, and I like where it sounds like it's going.
If I would change one thing, it would be that just before the key change you need some more buildup. It kinda just sounds abrupt to me, and I wasn't really expecting it. Unless that's what you were going for. In which case, good job! (lol)
Also, you should put like... a lead solo kinda thing. That would be incredible. I'd probably pay for that shit. That'd make my day.