Eidos has confirmed that news concerning a Batman: Arkham Asylum demo will be coming on Friday.
Speaking on the game's official forums, an Eidos moderator, posting under the alias of chip5541, made the announcement last Friday.
"I just got word that news concerning the demo will be coming next week."
There you go then. Tune in same bat-time, same bat-channel, to see what happens.
Apparently it's not news that is coming about the demo this Friday, but rather the actual demo itself, as stated on the Eidos forums.