Joe Mallozzi said in his most recent Gateworld blog entry that Season 10 of SG-1 and Season 3 of Atlantis are not at all confirmed:
“Contrary to the rumors, we have yet to hear word on the fate of either show – either from confirmed or uncomfirmed sources.”
He later said, in reference to the Season 9 cliffhanger now being readied for filming: “All I’ve got to say is – if there is no next season, there’ll be some major loose ends left dangling.”
How ironic would it be if, after several previous season finales tying up loose plot ends in anticipation of the end of the show, SG-1 actually did end forever with a cliffhanger?! We fervently hope this is not the case.