Summer, his notes will have lots of sources. The grand jury wants to know more than just what was said about Plame. According to the Appeals Court ruling that cites excerpts of the subpoena, they want his notes (and Miller's) on anything said about Wilson and his trip to Niger and uranium.
There definitely will be several names and that is why right off the bat I was very confident that Rove's name would be in the notes but it would turn out not to do with Plame and her role at CIA and/or recommending her husband.
Ruling can be read here: http://news.findlaw.com/hdocs/docs/plame/inregjmiller21505opn.pdf