ATS: Episode 12
Although it's been reported by a legit source and others have chimed into confirm, I have laid eyes on what should be the final word on who is appearing in Episode 12.
Angel: Episode 12
Yes, you can take it as fact that the 'Devil' himself will be appearing in Episode 12. Well, not that devil, but one that goes by the name of Izzy.
Angel is still extremely suspicious of Eve and requesting that security keep an eye on her while she's in the building.
Oh, and one other thing...
Cordelia is not only up and around, but she's extremely unhappy to discover exactly what Angel has been doing in her absence. More specifically, who he's gotten into business with.
(Thanks once again to 'T' for the timely info)