Here is a list of the changes you will see in Ubuntu 11.10 Alpha 2:
GNOME 3 – Finally, Ubuntu has made the transition from GNOME 2.32 to GNOME 3. By now, most the theme problems has been fixed. The default Ubuntu themes – Ambiance and Radiance – have been ported to GTK3.
Hybrid Image – The ISO of Ubuntu 11.10 Alpha 2 will be a hybrid image. This means that users no longer need the USB Startup Application to create a bootable Ubuntu USB drive.
No Synaptic Package Manager – The Synaptic Package Manager will be no longer installed by default in Ubuntu 11.10 Alpha 2.
Thunderbird as default email client – Ubuntu 11.10 Alpha 2 will not have Evolution as the default email client. Thunderbird will be installed as the default email client instead.
Linux 3.0 – Ubuntu 11.10 will be based on the newly released Linux 3.0.
Deja Dup – The backup tool, Deja Dup, will be installed by default in Ubuntu 11.10 Alpha 2.
Firefox 5 – Firefox – the default web browser in Ubuntu 11.10 – will be updated to the latest version.