FWIW, each turbo in the 335I (the name, by the way) is designated to provide boost to 3 cylinders, rather than have a small/large setup like the old Supras had. The reason for which, btw, was to eliminate lag while the bigger turbo was spooling. /tangent
Think of the I6 as two banks of 3 cylinders (kinda like a v6), then dedicate a turbo to each of the two banks. Granted, the turbos only provide a 70hp kick, but that's about a 15% gain in hp output for each turbo...not half bad...and there will be TONS of aftermarket. Oh...and with the 335i, there's NO lag. Take it from a 1.8t owner, Audi is going to have an extremely difficult time selling the 200hp FSI turbo a4's to all their turbo nuts with a boosted beemer in town.