Yes, he is a major risk to get injured again, given his last two years and also given his age. That said, every start that he makes with no apparent problems continues to reduce the risk. I acquired him 3 weeks ago for Mark Buerhle. Since I got him, he has gone 4-0 with an 0.90 ERA, he is just pitching ridiculously well. Since I gave up Buerhle, he has gone 0-2 with a 7.29 ERA, so I am liking the trade very much as of right now.
I would definitely be looking to acquire him if you can do so by giving up a pitcher like Buerhle (probably won't happen with how bad he's been lately), Glavine, Leiter, Washburn, Colon, or maybe Odalis Perez. With how lights out he has been lately, the owner may not give him up that easily, depending on how worried he is about the injury factor. I still wouldn't give up a Morris, Millwood, Hudson, Mussina or Wood to get Brown at this point though.