SmartCarb appears to split the gap between fuel injection and regular carburetors. It's a huge improvement on carb design in that it behaves more like fuel injection. Fuel injection is computer controlled and is the most precise but costliest form of fuel delivery. You will continue to see fuel injection on high end street bikes because the cost savings smart carb could offer is not worth the loss in computer controlled fuel injection.
Like I said, smartcarb is a niche product but a HUGE niche product. Don't expect to see them in GSXr's or Valkyrie s. But DO expect them in the millions of lower end bikes used overseas and in the developing world.
And not to confuse more, but those MotoX bikes getting high revs out of the smart carbs are 2 stroke engines while conventional motorcycle engines are 4 stroke.