Unfortunately I didn't get to watch last night, but just a few comments in response to yours. I am very, very excited about "Mamma Mia" but I have never felt that having Meryl play Donna was that great of a casting choice...just because Donna is really supposed to be probably in her early to mid 40's--and Meryl just looks too old...just my thoughts.
That's so cool that you are friends with Jesse Martin! He is super talented!
I remember prior to seeing Brooke Shileds in "Chicago" I was VERY doubtful about her...but you know what? She actually was great. Not only was she three months pregnant at the time I saw her (I can't imagine wanting to do anything but be near the bathroom or lie on my bed at that stage..) and she performed phenomenally well as Roxie. Is she a great singer? No--but she was adequate. Her dancing was great--much better than I expected.