they just ruled 5-4 against posting the 10 commandments in courthouses:
Justices left legal wiggle room, saying that some displays -- like their own courtroom frieze -- would be permissible if they're portrayed neutrally in order to honor the nation's legal history.
But framed copies in two Kentucky courthouses went too far in endorsing religion, the court held.
update: scotusb log is reporting that the second decision is in regarding the 10 commandments posted at statehouses.
Chief Justice William H. Rehnquist announced the second decision, finding no constitutional violation in the display of the Ten Commandments on the grounds of the state capitol building in Austin, Texas.
so... can't do it if it "promotes" a religion, but you can if it doesn't. we really didn't learn anything at all here, from what i can tell so far, though maybe once the text of the rulings is in, there will be something useful in there.