Legion was already upgraded by the reaper code; he was no longer 1183(?) programs in a single platform, he was one entity and the upgrade was a part of him. I think that's why he couldn't just copy it to the other geth, he had to rip it out of himself and he knew it would kill him. In order to have peace with the quarians he willingly made that sacrifice.
Today, I stopped TIM from taking over the citadel and said goodbye to Thane. When Valern made that little veiled threat after I cured the genophage, I would have gladly traded him for Thane, but what can you do. Also collected a billion more quests, invited Ashley back onto the Normandy, played a game of chess with Traynor, told James he should join the N7 program and had an interview with Allers. As everybody on board the Normandy knows, what happens in Shep's cabin stays in Shep's cabin, heh.
Liara told me about some trouble at an Ardat-Yakshi monastery. She's such a scatterbrain I bet she forgets all about those banshees we fought while tracking down Dr. Garneau and rescuing Dr. Bryson. Oh and Traynor told me about some Cerberus defectors. I wonder if Jacob still holds a grudge because I never spoke to him again after having his father arrested.
Why is it that Chakwas doesn't tell you about those medical supplies, and you don't hear about Din Korlack until you're back on the Normandy?