Still chugging through my replay.
Man, Tali comes into this game so bloody late. At one point I completely forgot that she joins the team. Also, I've actually been reading the text more. Dark Energy is what the Crucible uses...so it isn't entirely forgotten about; except when people don't actually explain what the Cruicble does or how they harness Dark Energy, you know, considering how it was a new threat, only six months previously.
As much I find the game to be well written on an intimate scale, it does sort of rush though the major plot points. The fact that you have to read the codex to understand Udina's motives is completely lazy, especially when Shepard is asked why by Bailey, and he replies, "I dunno!"
Also, at the hospital, I had no idea that the Asari's story is about...