If you just can't contain your excitement for Ubuntu Touch, you can flash the developer preview on your Nexus phone or tablet right now. The developer preview (which is in alpha stage and should be considered very experimental) is currently available for the Galaxy Nexus, Nexus 4, Nexus 7 and Nexus 10.
All you need is a computer running Ubuntu, some command line fu and nerves of steel. This process requires an unlocked bootloader and will wipe everything on your phone, so make sure you make a nandroid backup before you start. Hit the link below to see the full instructions.
Instructions for flashing a phone or tablet device with Ubuntu [Ubuntu Wiki via OMG! Ubuntu!]