For all the gory details check out coloneljack's transcript of the squee-fest here.
I just have to add that...I always knew The West Wing would deliver on the Josh and Donna relationship, but that episode exceeded all my expectations! Everyone's said it, but that kiss? Passionate, tender, hot, sweet...perfect. Just perfect. And the final scene?? Just sublime with all that smouldering UST in Josh's eyes...*melts*
And if Aaron Sorkin is reading - which I'm sure he is! - I think Danny should do lots of kissing in Studio 60. BW just does it so well!