I think this one's going out with a whimper.
(1) The statute [or state action, so let's substitute "the "school board's mandatory ID statement"] must have a secular legislative purpose:
They've blown this one completely. The school board is very much on record as having a religious purpose.
(2) The school board's mandatory ID statement's principal or primary effect must be one that neither advances nor inhibits religion:
Same remarks as above. Plus, the clear evidence that ID isn't science pretty much leaves any ID presentation in the religion category.
(3) The school board's mandatory ID statement must not foster "an excessive government entanglement with religion":
This is the fuzziest prong of the Lemon test, but I can see it shaping up as an endless involvement deciding which creation accounts get presented in science class.
So, this case seems to flunk all three prongs of the Lemon test. And flunking only one will suffice to sink the school board. It seems that no matter what the Supreme Court thinks of Lemon, they won't want to mess with this case.