We don’t have official confirmation of this yet, but Betty, and 5 other people have sent this info in. The YMS (Young Male Stars) homepage, in their Brendan Fehr section, is saying that the show is definately renewed. We will keep checking for official confirmation.
From: YMS HomePage
“Roswell” has been picked up for another 22 episodes. The WB has committed to airing 22 more episodes, insuring a 2nd season for the popular show.