Nokia has released the successor to the 770. It has the same screen a 4.1-inch, 800x480 pixel touch screen however there have been several other hardware upgrades; a 320MHz processor, 128MB of RAM, 256MB of Flash ROM, dual SD memory card slots, 802.11b/g WiFi, a built-in camera, and Bluetooth 2.0.
I could not find any details if the Linux OS has changed http://www.engadget.com/2007/01/05/nokia-n800-internet-tablet-unboxed/
