Just got home from watching Dreamgirls. To answer my question from Saturday: I liked it.
[12/19/2006 UPDATE: Actually, I liked it quite a bit. Jennifer Hudson was amazing, and she performed so well throughout the movie that it took some of the pressure off when she finally got to "And I Am Telling You..." because by that point she'd already established herself as fabulous. She performed that song beautifully, but after watching I realize that comparing her performance to Holliday is not really fair. It's like comparing apples and oranges -- Holliday knocked the top off of the song because she was projecting to a Broadway audience. Hudson's performance is different, it's more subtle and sad, and a bit less angry and desperate than Holliday's. I love them both.]
[UPDATE #2: Salon.com has a nice article on Holliday's rendition of And I Am Telling You.]