This is the most exciting thing you'll read all day. Are you sitting down? This is the all-new Aprilia RS4 125, a 125cc four-stroke RSV4 rep. Awesome. More details as they're available.
Update: turns out the RS4 125 is just a re-bodied Derbi GPR 125.
So yeah, compare the Derbi you see here and in the gallery below to the ‘Priller. Same aluminum beam frame, same Paolo forks, same braced swingarm, same radial breaks etc.
Of course that also means the RS4 will adopt the same under-stressed 15bhp 125cc four-stroke engine and will weigh the same 120kg/264lbs (not clear if that’s wet, dry or what). Fingers crossed that this comes to the states, the four-stroke engine is a good indication that it could.