I'm sure it can be done. I've heard about something very similar sometime in the last year or two, probably a cooking section on some other forum. I'm sure it was the combination of chocolate and bacon. At first I was a little bit appalled (back then) but after thinking it over I decided it might be good. I agree with what Girl49 said above, that sweet and salty are a good combination.
I'm sure the combination of brownies and bacon will please some people, although it wouldn't surprise me if some refuse to try it. After thinking it over I'm sure I would try it. I'll be looking forward to hearing how they came out.