On tonight's edition of WWE Raw, Triple H stated that he was giving Sting until the end of the broadcast to answer his challenge about a face-to-face confrontation between the two at the upcoming Fastlane event.

This seems to be a heavy indication that Sting may appear on Raw tonight in some form or another, though it is currently not known if Sting is backstage at the show.

UPDATE: It has been confirmed that Sting will indeed appear at Fastlane, as he accepted the offer from Triple H of a face-to-face confrontation at the event. Sting himself did not appear on Raw, but a message stating "Triple H, I accept" was shown on the TitanTron.