The SciFi Channel has announced that Stargate Atlantis will be airing new episodes through September 26th.
However, that's not all! It will then break for a week and return October 10th. On October 10th it will have a new airtime of 9PM. It will be the leadoff for a new SciFi program, Sanctuary, starring Amanda Tapping (who appeared in Atlantis). Sanctuary will be having a 2 hour series premiere the prior week.
It is still unknown when the 10 final episodes of this season of Atlantis will be aired. They might air in 2008 or be held off until Battlestar Galactica returns in 2009.
Source: TV Squad