MB is right. This could take a very long time. The writers strike certainly put things behind, and with Depp's schedule, and being so in demand, he definitely has several projects lined up, one of which, Shantram I think, keeps getting canned, then being greenlit again.
Just some food for thought:
The new "Speed Racer" movie that the Wachowski brothers are helming, is from produced Joel Silver, who says he's been shopping around the movie idea, trying to get it off the ground, for 20 YEARS! And then he finally found the right time, place, and people to bring it to life.
Alternatively, either the WB or Marvel (can't remember which off hand) is/was planning a Wonder Woman movie, which would help to kickstart the Justice League of America movie they're trying to get off the ground. Joss Whedon was attached to the WW project, to write the script, and after a year of working on it, he and the production company parted ways. Then the JL movie was canceled, so the WW project could take front and center, and last I've heard, the WW film is in the can, and they're trying to bring about JL all on its own.
So, as you can see, things don't really stay the same, or even in pre-pre-production for very long sometimes before things change. I think we're not going to hear much about the DS film until after 2010, and the film probably won't come out until sometime between 2010-15.