The writers originally planned to end with a cliffhanger finale, anticipating another renewal. But when word came in August of 2006 that SCI FI did not want an eleventh season of the show, they had to rethink how to end SG-1
's run on the network without ending the premise entirely -- similar to the challenge faced when the show ended its 5-year run on Showtime in Season Five.
The network did not want a cliffhanger
, Cooper said, and "out of respect for the fans we wanted that episode to have a little bit of a spirit of closure, a sense of ending without it being an ending. And thus we called it 'Unending.' It's one of those fun science fiction concepts that allows you to have a window into one possible version of the future for these characters."
(GateWorld news report)