The announcement that Falling Skies has been renewed for a third season should come out within the next day or two according to Variety's Stuart Levine. As noted over (and over) again the show's renewal has never been in doubt since it's TNT's top scripted drama with adults 18-49. Despite my hopes that TNT would stretch out the renewal as long as possible (there is surprising traffic both from fans as well as haters predicting the show will be canceled because they don't like it) my guess is the announcement will come on Tuesday (7/10). Last summer the season two renewal announcement came on Monday, July 7, 2011.
No info on the episode order in the Variety piece, but I'd look for another 10 episode season.