Most likely no, IMO. There are too many warning signs of some kind of a scam attempt (or an attempt to defraud some entity)
this, he have problem with taxes, his solution to handle this situation is bitcoin... there you are, scam written all over it
Yeah he would seem to have a motive but how exactly would pretending to be Satoshi help with his tax problems? Only thing I can think of is he says don't take my stuff for back taxes, because I have this hoard of bitcoins that I can't access until 2020.
From what I've seen if it isn't him it's one hell of a hoax, then again most of the information is from supposed leaked emails which obviously he could have leaked himself. The thing is this Gwern person who broke the story seems to be fairly respected, so for that reason I think there's still a chance. Too bad for them if it turns out to be a hoax. Sounds like Wired and Gizmodo we're racing to be first and may have cut some corners.