Joystiq (and other news sources) reported recently on a trademark Nintendo registered for the "V-Pocket". One assumption was that this trademark was for some kind of handheld device.
SPOnG.com claims to have "learned from official Nintendo sources" that the V-Pocket concerns PDA software Nintendo plans to release for the DS.
The article states:
Nintendo will soon unveil a complete suit of personal organiser tools for its Nintendo DS platform, expected to be shown before E3.