Thanks to Red Fountain Senior for the tip-off! :D
Here's a screenshot from the List of Winx Club Episodes page on Wikipedia. I know that Wikipedia can't alway be trusted, but according to this info, we won't have to wait very much longer for the 4kids version of season 4!
This screenshot is from the 4kids page on Wikipieda. For episodes, it lists 104, which would include the season 4 episodes. It also says that the series will "continue in Summer 2010"! Could this be true? We'll have to wait and see!