There is some debate going on in our theological circles over what it means to be "Reformed." Scott Clark has offered up a confessional definition in his book, Recovering the Reformed Confession. John Frame offers a response in this review of Clark's work. Both are probably worth reading. When you read a mainly negative review it's usually important to also read the book under review to make sure that the reviewer rightly understood what the writer had to say.
In the interests of full disclosure I do tend to side more with Professor Frame on this issue than with Dr. Clark. I think that Clark makes some good points in his book though I question or disagree with a lot of his conclusions. That said, it does need to be emphasized that "Reformed" means more than just believing in the five points of Calvinism but involves a worldview and practice of how we "do church" that goes deeper. Anyway, I'm sure you'll see more on this from both men and in the blogosphere.