The Ms2 is coming, at least that's what I've heard from a somewhat reliable source...Should see it peek in mid model cycle for 2016. He's heard small s roll turbo in the 175hp ish range weight right around 2400 lbs..That's all I got out of him, then he gave me the "oops I said to much" look.
As for the diesel....It sounds great on paper, but have you ever driven a performance car with a diesel? The TDI I autocrossed for a few months ( yeah that's how long it took for Tony to get tired of it), sucked. The torque was great, but so was the uncontrollable wheelspin and torque steer; unless you left the traction control on, then when you turned the wheel, it went flat with stability control. You run out of revs at 4,000 rpm and it's not very exciting to rev at all.. 3 shifts t 60mph.You almost want/need the DSG to enjoy the car. The diesel sucked the fun right out of the manual driving experience. S ,I'm not really looking forward to a diesel at all, and honestly, unless you drive 100+ miles a day strictly in bumper to bumper traffic, you'll never get the gain a diesel offers. Gas vehicles get just as good of MPG on the highway, at a substantially less cost per mile than diesel. Small bore Turbos are the future. Just drive the ST (either of them), fun fun fun..