Wow, I was surprised by this episode. I went into it expecting a humdrum run of the mill "Teyla's pregnant" episode. Instead Teyla's involvement was intensely toned down in favour of the episodes greater theme, the classic sci fi staple question of should mankind know the future. Deliberately or not, this episode reaches heights of philosophical complexity rarely seen outside of Battlestar Galactica. The stand out moment in the episode is the combination of the "fixed future" and "fluid future" philosophies, "The future is shaped by those who make it" is surprisingly profound.
The complications of knowing the future are believably portrayed too, with the visions shown without context actually complicated what should be a simple decision. The dark warning of things to come is a nice touch too, it'll give future episodes with the Replicators an extra edge of tension.
Finally, props must again go to the writers for finally making an episode where Sam Carter features prominently, but it unintrusive to the native cast. However, this praise does not signify my change of heart that her inclusion was a good idea, nor does it say I want any other SG-1 members on Atlantis (cameo or not).
One criticism, while the writers may have felt toning down Teyla's pregnancy was a good idea to keep mystery hanging in the air, a bit more information rather than a glancing scene would have been good.