Gridplane has revealed one of the many mock-ups it developed for Microsoft as a potential user-interface update, which later became the NXE. Tasked with creating new ways for users to interact with multimedia, this particular mock-up showcases some of the style found in the NXE. Notably, the use of full retail packaging to list titles and the panes of information, such as the disc in tray image for Halo 3, can be found on current Xbox 360s.
Gridplane also mentions that they dreamt up an "immersive 3D environment" for users to explore games and events within the Xbox Live Community. Which, to us, sounds suspiciously like Sony's Home service.
While the mock-up is stylistically impressive, it all looks a little too much like we forgot our glasses somewhere. Luckily, the final NXE nabbed some of the best ideas and ditched the whole "ethereal plane" look this version seems to evoke.