there is so much crap info (best way to describe it) floating around right now and I think its all just guesses that these magazines are reporting as fact from their "sources".
Left Lane News is saying 2 turbos, which I can see, but maybe thats just because the "tri-turbo" is really 2 regular turbos plus some electric device and BMW might still just call it a twin turbo (since turbo is exhaust driven).
as far as the actual engine and the report of an enhanced N55 engine, do you really think BMW would do that? I mean they did it for the 1M but thats a different beast, I could see them taking a N55 and turning it into a 3.2L and then adding two large turbos but that is still a completely new engine, not just an enhanced N55 (just my opinion). If in fact it is just a N55 with an extra turbo, 430HP like the article suggests, then they are going to lose a lot of sales to Mercedes and Audi,
Especially if the price is the same or higher than the current M3, not many will pay $70K for a loaded M3 that is using a N55 engine with an extra turbo.