I don't understand, what is so exciting, the stripes ? the M135i will be an 135i with Power Kit (+20 lousy hp) and M-Sport suspension and a few other tweaks including dozens of M badges.
Sounds like the same engine that's in my 2011 E90 335i with the performance package. Frankly, I don't know why BMW doesn't just make the 320 bhp version of the N55 standard vs. the 300 bhp version that shows up in their cars with the N55 in the US market. It seems like I get better gas mileage along with the increase in performance since it was installed. I wouldn't think that the cost would be any different, plus most folks who opt for a N55 over the N20 are looking for extra performance anyway.
'11 BMW 335i (Alpine White) M-Sport, Premium, Heated Seats, HK, Ipod adaptor, dealer-installed PPK - Euro Delivery 5/11/2011
'05 Lotus Elise (Arctic Silver) Sport, HT, Stage II, Odyssey PC925
'87 Nissan Pickup (Burgandy) King Cab, 80k miles
'13 Audi A3 TDI (Ibis White) Cold Weather Package, Bluetooth - Wife's car - Delivery 9/12