I've had the pleasure of using this device (secretly) for the past few months and I really do like it! The Treo Pro adds WiFi and GPS in a much sleeker form factor than both the 500 and 750 devices.
It is also a Windows Mobile 6.1 professional device so comes with all the latest Windows Mobile capabilities built in!
Check out the video above or head on over to the Palm website for more information - http://www.palm.com/treopro
Feel free to post comments/questions about the device and I'll try and answer them!