Another bit of possible proof that Origins will get a 3DS port surfaced on Ubisoft's official blog for Origins a few months ago. They stated in a short entry that in addition to the game coming to PS3 and 360 in the form of downloadable episodes, Ubisoft would consider putting it on other platforms. They specifically named 3DS, Wii, PC, and iPad as considerations for other platforms. The rating also mentions that the game is "multiplatform", further giving this theory some evidence.
On the flip side though, this always has the possibilities of being something else entirely. It should be noted that the GBA got Rayman 1 as a launch title. DS got Rayman 2 in the form of Rayman DS near after its own launch. If you take that trend into consideration, perhaps this will be a port of Rayman 3 on 3DS, optimized to use the 3D effect? Or perhaps even a totally new Rayman game? Or something totally unexpected, perhaps not even 3DS-related at all. At the moment, it's looking as though the Rayman Origins rumor might be the most valid, though one wonders why they call it "Rayman 3D" instead of Rayman Origins (since the game has already been revealed for the HD consoles)...
At any rate, you can probably expect an official followup announcement from Ubisoft pretty soon. Perhaps within the next couple of days. There's always the possibility of this being just a rumor and a mistake on the part of the ratings board who listed it, but that would be a pretty huge mess-up on their part. We shall see soon though. It should also be noted that Rayman Origins Episode 1 was intended to be released on PSN and Xbox Live for the two HD consoles this Christmas. There has been no followup stories about the game since around E3 though, and no advertisement from what can be seen. It would appear that the game may be getting a delay until next year. Perhaps they are going to spread the release out over several consoles and decided delayed the game due to porting reasons. The 3DS in particular is launching around March. [/p]