I've heard back from a few people now who contacted Google about the issue of indexing creationist sites in Google Scholar; these are informal remarks from the team, not an official policy statement, but they're still interesting. And revealing. And useful. They'll change your perspective on Google Scholar.
The premise of the petition to Google to stop serving up creationist claptrap is a misconception. Google Scholar does not index on content; it can't, it's just a dumb machine sorting text. Google Scholar does not, and this is the surprise to me, index on the source — it makes no decision based on whether it's an article from Nature or from a kindergarten Sunday School class fieldtrip. There's nothing they can easily tweak to exclude garbage from one source and include jewels from another: the internet is one big garbage heap to Google, and they'll dig for you, but it's your job to sort gems from trash.
The way items get on Google Scholar is based entirely on whether they're formatted like a scholarly paper. They aren't sharing the details, but it has to be fairly general stuff, like having a title and author and not being surround by advertising bric-a-brac, or whatever. Any ol' nonsense will do, since they don't evaluate content, and any ol' author will also do, since they don't care if it's being published by the university or the insane asylum, just make it look sort of like a serious paper, and it will show up.
And now you know how Answers in Genesis can find their twaddle on Google Scholar. If there's anything they're good at, it's pretending to be scientific, going through the motions while demolishing the substance. This is good information to have, actually, and you should pass it on to your students, and take it into account when using the service.