I registered just to post this reply, so hopefully the picture I posted linked up correctly here.

I tried hammering in a wedge as suggested by farmermanmatt above but my rotor just wouldn't give. Here's how I solved the problem.

Remove the caliper; we'll be using the same gap between the bracket and rotor dust cover that farmermanmatt described. You'll see that the bolts that hold on the caliper bracket occupy about half of the space in this gap when fully tightened. Back the bolts out until they are no longer exposed in the gap. Wedge a hardened piece of metal in between the caliper bracket and rotor dust cover and position it so that it covers the bracket bolt holes (pictured.) Now tighten the bolts again. They will push your wedged piece of metal against the rotor and push the rotor off. Once I figured this out I had the rotor off in just a couple of minutes. And, it doesn't damage the rotor at all, so you can simply have it turned and re-install.

The piece of flat metal that you wedge in to do this should fit snug, around 3/8" thick or thereabouts. The piece I used was an old extra arm from a garage door opener that I had laying around. I hope this helps someone.