The 2010 still has a +52.5mm offset. I was curious about the wheel size so I stuck my phone inside a 2010 wheel at a dealership and snapped a pic of the back of the spoke with the dimension info cast into it. It says "18x71/2J 52.5".
The calipers are probably not literally identical to the 07-09 car, but I very much doubt they've changed enough that you can no longer mount a 16" wheel. Certainly, a 17" wheel should fit. DailyDriver, all that's needed to outift the MS3 for "serious snow action" is a set of 16" wheels with any dedicated snow tire. I like Blizzaks too, but they're best in deep snow and can wear out quickly on long dry freeway slogs.
Also, guys, instead of clammoring all over the forums and getting back answers like "2010 speed3 have bigger brakes" with no substantiating info, feel free to go to some tire shop and test fit a 16" or 17" wheel. That will answer all your questions beyond a shadow of a doubt. Also craigslist works well to pick up used winter set-ups, and you can test fit them before you buy.