The accelerometer is now tied to hard-drive protection hardware as well as screen-orientation.
Larger, more robust
The handle can now recess into the Classmate; the larger screen yields a larger device that, according to Intel, has been better-received by older students but is still accessible even to Kindergartners.
Easier, multi-position swivel camera
The camera on the previous generation Classmate swiveled from front to back; the mechanism has been improved in this iteration to allow viewing from all angles
Touch-enabled e-reader applications
No multi-touch yet (the cost is still too high), but the e-reader applications have limited gesture support for interacting with e-books naturally.
95% of full-size keyboard
Improved accessibility for a wider age range with a slightly larger keyboard (enabled by the larger screen).
10.1in screen e-reader
This is right in iPad territory, but it has an educational content ecosystem and a keyboard.
Previous generations compared
The clamshell Classmate also received an upgrade to the larger screen; this picture shows the 9 inch models vs. the 10.1 inch models.
Micromobility - not so micro
Intel talks a lot about "micromobility" or the way kids tend to take their work to comfy spots and work together or independently. The larger Classmate remains portable but provides a larger area for viewing and creating content.