A link to a WMV movie of a rotary engine that is NOT a Wankle. It has been built and it's being tested in a Yamaha scooter. The manufacturer claims the engine can give you the same torque at half the RPMs - I don't know if that's half the RPMs of a piston engine (which is implied) or a Wankle, which would be a fair comparison.
The part that's got my attention is the whole guide grove. That looks to me like something that will get a lot of wear and tear over time, especially with the pressure of the ignition cycle pushing outward on it, never the less, I find this interesting and like to see it at least put to a fair test.