Looks like Kaley Cuoco won't be appearing on the Grey's Anatomy finale after all, as previous reported by Entertainment Weekly.
Cuoco backed out of the gig due to a "publicity commitment", though the rumor mill is claiming that the real reason was more along the lines of "They [CBS] didn't want one of their biggest stars appearing on one of ABC's biggest shows."
No matter what the reason...Cuoco's definitely out and Shannon Lucio - who appeared in the second season of The O.C. as Caleb's illegitimate daughter Lindsay - is now in.
It's still unknown what this mysterious role even is...!