The Undertaker has not been seen in Dallas, Texas where RAW is being taped, at least as of 7 PM ET. While it is possible that he's being hidden, it is more likely that he won't be at the show.
There could be a tease (lights out, gong, etc) tonight like I talked about last week on WZR Radio. I do expect Triple H tonight. Two big returns in one doesn't make sense. It's all about ratings and spreading things out. There is no need to rush it all in one night.