Info on Season 8 & Atlantis:
According to spoilers available for the series premiere of Stargate Atlantis (which will include cameos from Jack O'Neill and Daniel Jackson), O'Neill will recover from his dire predicament in which he is left hanging at the end of Season Seven's "The Lost City" -- and will be promoted to general.
Still unconfirmed is the news that O'Neill will replace General Hammond as the commanding officer of the S.G.C. (Dr. Elizabeth Weir will depart to command the Atlantis team in another galaxy). Also unconfirmed is a rumor that SG-1 will become a 3-person team, with O'Neill occasionally joining them for field missions (thus enabling the writers to deal with actor Richard Dean Anderson's reduced schedule in a way more easily explainable than his frequent departures from the story in Season Seven). This would, by all accounts, leave Carter as the commander of SG-1. Confirmation on the above should be forthcoming.
The producers intended to set up the premise for Atlantis with an SG-1 feature film, but instead tell that story in "The Lost City," the 2-part finale for Season Seven of Stargate SG-1. Creator Brad Wright told fans that the new series will not be based on a military team. Executive producer Robert C. Cooper has said that the film's story "evolves the Stargate."
The new team finds Atlantis, the mythical lost city of the Ancients (the builders of the Stargate network), in the distant Pegasus galaxy. This is the setting for the series, as they set up a new base at Atlantis under the command of Dr. Elizabeth Weir.
A team of scientists has been pouring over the Ancients' Antarctic outpost since SG-1 discovered it buried a mile beneath the ice in "The Lost City," and have learned that only people with a very rare gene are able to operate the intuitive technology found there -- one person in 16,000, to be exact. Dr. Benjamin Ingram is a brilliant scientist who works to interface Earth technology with that of the Ancients, but is frustrated by the fact that he himself does not possess the gene. Another of the scientists, however -- Dr. Beckett -- does possess the gene and accidentally launches an Ancient attack drone from the outpost. They also quickly learn that Major Sheppard has the gene; the ability to use the Ancients' tech will come in very handy when the team reaches the lost city of Atlantis in the distant Pegasus galaxy.
Vital to the operation of the city (and to the team's ability to gate to another galaxy) is the Z.P.M., an Ancient power module that was probably the basis for the device O'Neill constructed in "The Fifth Race" while under the influence of the Ancients' library of knowledge. Atlantis is powered by three of the devices.
As hoped, the lost city is indeed a treasure trove of advanced technology, which includes such things as a universal translation device. Each team member travelling off-world receives one, which is capable of instantly translating virtually any language encountered.