You have to be kidding.

Rating: 3/10 (1 May 2008)

"Dramatic validity": Do the characters behave like real people would in these circumstances? No. Juno behaves like a grown-up, and an emotionally reserved one, at that. The adoptive parents behave like self-absorbed teen-agers.
"Well-drawn characters": Are the character's actions dictated by some internal logic? No. The author just pushes them around the set like cardboard cut-outs. Juno decides she's in love with the guy at the end - not because it makes sense - but because it's cute. The step-mom bad-mouths the ultrasound tech, not because there's any reason for it, but because it's cute.
When I read that the writer got an Oscar for this abomination, I thought it was a joke. The author clearly doesn't know anything about plot, character development, or dialog. She just knows how to be cute.
Now, then, the movie does deal with a serious issue. Yes, unprotected sex can lead to unintended consequences. You can get so upset, you have to pull your family's mini-van on to the shoulder and just C-R-Y! I'm giving it 3 stars only because the Ellen Page did a great job acting. It must have been very difficult for a teen-ager to behave like a 35 year old. Oh, yes, the author told us, in so many words, that she has an old soul. Well, that explains it all.
This was 90 minutes of "Look at me I'm so cute when I'm knocked up."