Back at UDS-Oakland for Ubuntu 12.10 there were discussions about A GNOME Flavor Of Ubuntu - "GNOME-buntu". Those discussions are still ongoing and it looks like they're beginning to settle on using the name GNObuntu.
For the GNOME-ified Ubuntu spin they don't want to go with the name "Gubuntu" since it could be easily confused with Goobuntu, Google's internal re-mix of Ubuntu for its employees.
The plan to use the GNObuntu name was expressed in an email to GNOME when Jeremy Bicha of Ubuntu was asking if it's okay to go with this name.
Beyond the name, and that it will use the GNOME Shell as the default desktop environment, not many other details are known at this time.