GDC does sound like a weird place for Nintendo to announce anything major it might just be behind closed dors showing of a prototype new platform to developers or something with an actual announcement at E3.
Also I reject the idea that Nintendo wouldn't release a new hand held just because of how well DS hardware is doing, if you look at the data for the software side the Wii is much stronger and there aren't many major DS releases on the horizon. Just because a new platform is released doesn't mean that nintendo would kill the DS like microsoft did with the Xbox, I think the DS would be much like the PS2 where it remains strong a good while into the next iterations life. Another thing to remember is that the GBA micro came out after the DS was released so new DS hardware like a DS mini or something could still be released after a DS2 is released.
@TheVoxelman on twitter
