CyberConnect2, the developer for the .hack titles as well as the PlayStation line of Naruto titles, has put up a new countdown site for a new Nintendo DS project. Up until now the developer has been focused mainly on PS3 and PSP projects.
It's unlikely this title has anything to do with the Naruto series since other developers have handled the series on Nintendo's platforms. There is the possibility this title may be related to the .hack series, since a piece of concept art for an unnamed Nintendo DS title back in 2007 featured the tagline "To the World", which has connotations to the series.
The countdown is set to end on March 18 in Japan, which is around the time Famitsu is released, which almost always gets leaked early. The developer recently just completed work on .hack//Link for the PSP and is currently working on a sequel for Naruto Shipuuden Narutimate Storm, which will be released on the Xbox 360 and PlayStation 3.