HI,
Season 3 of "NYPD Blue" should be out on Region 2, probably around March/April 2004, with Season 4, around October/November time.
As the show is still being shown, here in the UK, they are not releasing the sets more than two seasons per year, as the show is being aired on both Channel 4 (Season 9) and Fox's own FX-UK network on Sky Digital (all episodes to date, chronologically and uncut, with the missing episodes C4 dared to censor/not transmit)!
Pooch