I'm presuming you're going to need to build an unbuntu compatible kernel for the note, mobile devices don't tend to work in the same way as desktops, so the pretty much universal kernel model used on the desktops don't work too well here. (size being the major consideration).
Not really looked into what they are doing, I'm presuming they will release source under gpl, so at least you will be able to diff a standard gnex build and the ubuntu. You can then use that as a basis to rebuild for the note.
"Porting" an image if that's all they release is going to end up quite messy.
EDIT according to techradar they will release source http://www.techradar.com/news/softwa...t-week-1131567