It looks like 90210 star Shenae Grimes is about to get it. She just posted a photo (left) on her twitter with the following text:

On set waiting to bang out my cameo in scream 4! All hush hush but stay tuned! X

We say… What? That came out of nowhere…

Update: BananaDoc posted 1 hour ago: No sign of Kristen Bell or Anna Paquin on set tonight. Clearly I’m a little behind on pop culture, but word is that there were two girls—someone from Degrassi and someone from Pretty Little Liars?

That pretty much confirms it… Thanks to @Scream4fan for the heads up!

Update: Lucy Hale is the "Pretty Little Liars" star on the set!