Howdy,
Exciting news out the festivities this weekend at Maker Faire NYC and the Open Hardware Summit. Arduino has announced a new board called the DUE which uses a 32-bit ARM Cortex-M3 microcontroller! They have a full breakdown on their blog: http://arduino.cc/blog/2011/09/17/arduino-launches-new-products-in-maker-faire/
Other goodness includes an improved & lower cost version of the Uno called the Leonardo, an official Arduino Wi-Fi shield and finally the 1.0 release of the Arduino IDE.
Here's a vide of the Arduino team's presentation:
Cheers,
Drew