The Ubuntu Touch Developer Preview should be available for download later today and although I've found some daily images which can already be downloaded (I won't give you a download link but if you can't wait for the official release, you can do a Google search), I unfortunately don't have a Nexus device to test them on.
Update: the Ubuntu Touch Developer Preview has been released.
Update: the Ubuntu Touch Developer Preview has been released.
But some Ubuntu for tablets hands-on videos have already started to show up on YouTube and below you can watch two of them, via Engadget and TheVerge:
(direct video link)
(direct video link)