Josh Hutcherson (Cirque du Freak) and Alice in Wonderland's Mia Wasikowska play the kids, and Hutcherson convinces big sis to find out who gave their moms the donor sperm. The lucky man happens to be Mark Ruffalo, who is both freaked out and intrigued by the news that he has two kids with lesbian moms. Things get iffy, however, when he gets close to Joni (Wasikowska) and his presence starts revealing marital discontent in Moore's Jules. (As a side note, in one scene, you'll see a girl calling Ruffalo a "stone cold fox" -- that's Zosia Mamet, the straight girl crushing on Marshall and headed for heartbreak in United States of Tara.)
If the trailer isn't enough to sway you, or Kevin Kelly's review, maybe the gushing over at Salon will: "The Kids Are All Right ranks with the most compelling portraits of an American marriage, regardless of sexuality, in film history." It may have taken seven years to get completed, but it looks like it's worth it.