I'm actually looking forward to smart rollers. There are a few out there already.
Elite makes an ANT+ E-Motion roller which can be used with Zwift but the reviews claim that the resistance is a little choppy.
The InsideRide E-Motion with ANT+ smart resistance unit is reviewed very well but the price is as high as the most expensive smart trainers.
Neither are compelling enough to make me want to join Zwift. The E-Motion rollers are a cool idea though.
-Tim-