Just upgraded my XO 1 to the latest Q2E45 firmware and OS build 852. And I must admit that I really like the new feature Switch Desktop to Gnome:
Step 1: go to My Settings:
Step 2: click on Switch Desktop
Step 3: click on Switch to Gnome
Step 4: confirm by clicking on Restart now
and voila, you are now running Gnome desktop environment on your XO 1 (w/ approx 380 MB of free space left).
Links:
[1] http://linux.philosweb.com/drupal/category/it/it-general
[2] http://linux.philosweb.com/drupal/category/it/software/software/os/linux
[3] http://linux.philosweb.com/drupal/category/it/hardware/olpc
[4] http://linux.philosweb.com/drupal/system/files/image_2_130.png
[5] http://linux.philosweb.com/drupal/system/files/OLPC_852_20101224_000_2.png
[6] http://linux.philosweb.com/drupal/system/files/OLPC_852_20101224_004_2.png
[7] http://linux.philosweb.com/drupal/system/files/OLPC_852_20101224_002_2.png
[8] http://linux.philosweb.com/drupal/system/files/OLPC_852_20101224_001_2.png