Thinking more about it, I would still guess that, given Canonical is already allowing the project to use Canonical’s “Unity” mark, Canonical would probably also allow the group to use either of the previous two logos that I proposed, provided permission were properly requested. But again, that’s just my guess.
However, if I’m guessing wrong, then here’s an alternative that may be permissible:
As before, the colors could be changed, such as to purple and white, or purple and orange, or whatever appropriate.
I hope that @d0od likes that dots inside the Unity U.
But just to reiterate, of all the logos proposed on this page, my first preference is the well-established Unity logo provided by @Wimpress. It’s simple, clean, and recognizable.
Of the logos that I submitted, I prefer either of the logos that incorporate the whole Ubuntu logo, provided Canonical would permit using such a logo.
I’m only submitting this logo as a fall-back, just in case Canonical doesn’t permit using my more preferred logos.