Agree with all the comments, what a wonderful, stunning episode.
I happened to read a TV guide preview yesterday which described it as possibly the best TV of the decade so I anticipated it would be good and still it didn't disappoint. The only thing I could kick myself about is that, really, I'd rather have not known and be taken by even more surprise by quality of it (if you know what I mean!).
It was incredibly moving, especially Don's reaction to the death, from the way he refused to take the call and then all the way through to the manner in which he broke down. Incredible acting.
And I LOVE Roger. He probably gets some of the best lines in it.
I watch this series with my son and we both agree that it's the best thing on TV and we never want an episode to end. I even loved the music it ended with last night - was it Simon & Garfunkel?