I think most Ubuntu users who are GNOME fans want there to be a successful and popular GNOME flavor of Ubuntu.
And if we're going to ship GNOME 3.6, we might as well ship all of it, right?
On the other hand, there are huge advantages to becoming an officially recognized Ubuntu flavor.
Canonical will supply the bandwidth for our images so that we don't have to force our users to use torrents.
Official daily images (For 12.10, since we're unofficial we may only have as few official images as one Alpha, one Beta, and a final build.)
Canonical builds the images for us, which saves a huge amount of time and effort and will end up significantly improving the quality of the images.
Equal status with the other recognized flavors
Far more users, as it's easier for users to use our releases and our releases are more trusted since they are coming from ubuntu.com infrastructure.
More consideration for bugs that badly affect the GNOME remix (or similar GNOME remixes)
I believe an official Ubuntu GNOME flavor will get more attention than UGR or the Ubuntu GNOME Shell Remix got.
We will have a better, more successful product if we are a recognized flavor.
One of the rules of official flavors is that they must not use PPAs. It's hard enough to become a recognized flavor without trying to bend the rules.