Season 1 - November 12, 2002 (Warner Release) Season 2 - June 3, 2003 (Warner Release) Season 3 - December 16, 2003 (Paramount Release) Season 4 - July 2004 ??? (Paramount Release)
That's my prediction at least. I'm guessing early July, like the 6th or possibly even late June (22nd or 29th). Then Season 5 in December, but a little earlier this time around (7th or 14th) so it can take full advantage of the holiday shopping period.
Please keep in mind that this is all just MAJOR speculation on my part as I haven't heard any possible dates either.
Joshua's guess, while admittedly just a guess is also what I would be hoping for in terms of a time frame. I'm really glad to have all 3 seasons on DVD, and would welcome a couple more this year if Paramount saw fit.