I really don't think you can single Canonical out about wanting to offer a differentiated user interface with their Unity offering. They aren't the only ones building differentiated interfaces. Meego has a differentiated user interface which leveraged existing Gnome technologies. Litl's interface is essential a differentiated (and proprietary) user interface on top of GNOME technologies (and derived from Ubuntu as well, but doesn't actually use any of Canonical's in-house built technologies afaik).
Canonical's OEM servicing business strategy really puts them in a tough position because its ultimately OEM interests which are driving what Canonical is building in-house. If OEMs want a differentiated stack and want it by a specific delivery date... who other than Canonical is there expressing an interest in being paid to do the work? If there were not OEMs looking for differentiated stack, Canonical wouldn't be building them.
Take for an historic example the Mi interface created by Canonical and paid for by HP. Unity could end up just like the Mi interface, functional and utterly forgotten once its clear that the software doesn't actually help the sponsoring OEMs sell devices. We really won't know the fate of Unity until we start seeing how the Unity based OEM pre-installs from Canonical partners fare in the marketplace.