Its funny you mention that, because I'm pretty sure they come out In june, but comingsoon.net has them coming out at the end of may.
http://www.comingsoon.net/dvd/bd.php?year=2008&month=5
Pretty much everywhere else though shows news to the contrary.
It would be cool if they came out early though.
Is There Will Be Blood that good??? People really mark out for it on this site.
I'm gonna have to check this out.