The Somnia mod is a mod for singleplayer that lets crops grow at night, and other things happene at night. Is it possible for someone to do something smiliar?
I think this could be doable, but bear one very important thing in mind... MC servers only update the blocks where players are present to save as much computation time as possible for its smooth run - this plugin would have to force Bukkit to update all areas where players have homes and farms at least, possibly slowing the server to a crawl with 50+ players online at any time not to mention devising logic to check which locations to actually update, which were abandoned and would not bring any good if they were updated etc.
