I don't know if this is new or not, but I was browsing Gamasutra's job listing, (The web presence for Game Developer Magazine) and came across 2 job listings for Rare looking for a Lead Artist and Game Programmers specifically for the Nintendo DS. Usually if they are going through the trouble of looking for help it a sure sign that they are going to be developing titles. Here is copy of the listing, they were two liners among some bigger ads.
Rare - Microsoft Game Studios -- Atherstone, WA CV9 3QN, United Kingdom
GAMES PROGRAMMER/S (NINTENDO DS)
Rare - Microsoft Games Studios -- Atherstone, WA CV9 3QN, United Kingdom
LEAD ARTIST (NINTENDO DS)
It's near the end of the listings.