Yes, that seems to be the idea being thrown around at the moment. I very. very much doubt that Snape is Reg. But the blonde deatheater...perhaps.
Reg may not even be alive...we aren't told how old the note actually is (I don't think...I haven't got HP on hand to check) and Sirius did say he was killed by Voldemort...but hey, this is Harry Potter we're talking about, a small thing like apparently being killed isn't going to stop someone from reappearing in the story if they want to
