Yes, Byron, cutting and pasting chunks from RNC press releases and passing it off as "journalism" is plagiarism (as is stealing from the Associated Press). Using blogs as a research tool and then using the information discovered in them quite possibly isn't, depending on the specifics.
It was certainly sloppy of the Brown campaign, but politicians take from research done all over the place all the time. Talking points are issued and reissued (and repeated). If Brown had given a speech just repeating everything in the post I'd see it somewhat differently, but passing on a bit of oppo research or set of talking points is pretty much standard stuff.