I do think that it is a "conscious" move by Nokia to not allow it in the Ovi Store since they made those official videos demoing the games. Also I think a couple of tweets suggested that they are coming to the Store. Just check out http://maemo.nokia.com

My guess: Will be announced with Nokia's first MeeGo device to give the platform some impressive games from the get-go. It will then also be available for the N900.