I been playing with the new PF motors. They are absolutely fantastic - it is easy to attach to the beams, and have incredible torque. They are smaller than the NXT motors (see the LDRAW sketch of it below in last week's post from Matthias) - in fact it comes in two sizes - the smaller one with slightly less power and the XL version with more grunt.
Currently you need the Infrared remote to control the motors. However, soon you would be able to control the motors directly from the NXT using third party IR bridge sensors when they become available.
The motor comes with its own power pack (with space for 6 AA batteries) which also powers the IR receiver. The IR remote transmitter takes three AAA batteries. I managed to get nearly 3 hours of playing from a full charge - so it is pretty impressive.
Here is a video of a NXT robot powered by the new PF elements. You can find out more about the project on NXTLOG.