The official Sony line is that Sony Japan is having a terribly difficult time meeting its own demand for the handheld. It's having such a difficult time that PocketStations in Japan are scarce and only a handful of them are supported by games. Initially the PocketStation was to launch sometime this summer at latest, according to insiders at Sony. There was, however, never an official launch date.
Furthermore, because the situation looks so dire, Sony can not determine when the PocketStation will come out - if ever. So, the score is PocketStation 1 - gamers - 0. Sony, standing on shaky ground, has no solid plans for its future release that it can discuss at this time. A sad commentary on a great company that's more capable than any other in the videogame industry to bring out something not as powerful as a Game Boy.
We'll have more when Sony rings out any new information on the PocketStation.