One guy only wanted to buy a Nexus S from eBay. Instead, the lucky fellow got more than just Android 2.3 Gingerbread–he got a Nexus S allegedly running the Android version destined for the upcoming Nexus Prime–Android 2.4/4.0 Ice Cream Sandwich (ICS)–and caught it on camera, too.

Engadget got a copy of the footage and reported that the source found Android build IRK48 and kernel 3.0.1 on the Nexus S that the source bought from eBay.

True to Google’s promise of bringing together the best elements of Android’s smartphone-optimized fork (Android 2.3 Gingerbread) and Android’s tablet-optimized fork (Android 3.2 Honeycomb), the ICS version running on the Nexus S showed a wildly and drastically improved interface that does “unite” Gingerbread and Honeycomb.

For instance, a Honeycomb-inspired, vertical multitasking menu appears when a long press is made on the home button. The camera’s user interface, the notification bar, and the other menus also looked different–not exactly Honeycomb-like, but not exactly Gingerbread-like either. They were rather, er, ICS-like.

Engadget also notes four shortcuts (instead of the two in Gingerbread) at the bottom. A new Google Apps icon opens a screen containing the icons for Google services such as Google+, Gmail, Maps, YouTube, Music, Videos, Books, Android Market, Calendar, and Gallery.

Is the video a fake? Skeptics have theorized about the various possibilities that the video could have been faked. For one, it is possible–though rather unlikely–for someone to create a custom ROM and custom launcher, and pass it off as legit ICS.

A member of the XDA Developers forum recently claimed ownership of the video that Engadget published and of the eBay-bought Nexus S reported in the Engadget story. The user sought help from other forum members after his Nexus S became unusable. Google was reportedly able to remotely wipe data on the device.

Members of the XDA Developers forum swooped in on the said user, hoping to help the user save the phone’s data (especially ICS). At the moment, no one could say for certain whether the video or the software on the phone was a hoax.

Several forum members, however, dismissed the possibility of a hoax. One member pointed out that he has not seen any custom ROM or app similar to the one shown in the video. Another forum member pointed out that the software on the Nexus S was probably an early build of ICS and could not have been a hoax since a lot of coding time and effort would have been spent just to produce the functionality and user interface demonstrated in the video.

If Android 2.4/4.0 Ice Cream Sandwich did turn out to be just as the video has shown, why or why not would you like it?