CycloCross

I'm really spoiled living where I do. Cyclists in the Milwaukee area are lucky to have an organization like the WCA who sets up racing series. This summer I rode in about a third of the Wisconsin Cup races and I had a great time and well surpassed any expectation I had.

The WCA also organizes about 10 cyclocross races in the fall, the schedule is here. I've been doing some reading and I'm real interested in giving this a try. I want to keep my fitness up this fall without having to whip out the trainer too soon. Plus, a brief cyclocross season will let me focus on something other than work and school ... (i just got my econometrics syllabus and want to cry!)
My problem is that I don't have a cyclocross bike. Does that sound like a problem, or a problem with a really simple solution! I think the Trek XO 1 will be my final choice. I'd be thrilled if I can find an '07 model seeing as the new '08 models just came out and are more expensive.