I feel bookending the series is an excellent way to end it. Here's a serise that has managed to last 10 years and still manage to get better. It's time for its story to end - as much as my selfish mind wants to see more. Besides, the Tau'ri were getting too powerful - as hinted at in "200". Now the writiers had to pull out anti-ancients to go up against, I mean, who's next?