It seems that French gaming sites are breaking a lot of Nintendo headlines these days.
Gameblog (link is in French...obviously) sat down for an interview with Nintendo bigwig Shigeru Miyamoto, who said "I promise to do everything to release the new Mario this year" (my translation), and that the team working on the game is most likely one that was behind the Super Mario Galaxy games.
"New Mario" is a bit vague, but only last month Nintendo revealed it's working on a Mario title for the 3DS, so it makes perfect sense that it is that game. That being said, doing everything to release something is not the same as guaranteeing it will be released, and Nintendo has a history of slipping release dates. One would expect a new Mario game would take time to complete; however, if the Galaxy team is using existing architecture, the 3DS's first Mario title could be quite far along - and Mario Galaxy would be a perfect fit in 3-D. It would also be a perfect fit as a AAA holiday title for Nintendo's new handheld, so perhaps it will actually happen this year...?