It has recently been spotted that Nadeo, the developer of the extremely popular TrackMania series of racing games, is looking to branch out into other genres, namely those of the First-Person Shooter and Role-Playing Game, with 'ShootMania' and 'QuestMania' planned for unspecified formats (although PC is likely to be a given considering Nadeo's track record).
For now this is all that is known, although a director at Nadeo confirmed that this is no joke, as some first thought, and that a launch window will be revealed in the next week or so.
In the meantime, be sure to check out Cubed3's review of TrackMania DS.