Weighing in on the 2 teaser/promo's....
One is obviously Kane, the mask etc. Hopefully he'll come back masked. There's no real need for it, it'd just be cool.
The other, the 'it begins' promo, I think, is Jericho. I can't see it being The Undertaker, because 'begins' just doesn't suit him. I think everyone knows that Taker has 1 more match in him, Wrestlemania. You can't elude to something 'beginning' with A. his history and legacy, and B. the fact he most likely will not wrestle until Wrestlemania.
If I was to predict what this means for Wrestlemania, I'd go with...
John Cena Vs. The Rock
CM Punk Vs. Jericho (for the title. Jericho possibly coming back 2nd January would give him just under 4 months to start his movement against Punk, and to change the WWE his way.)
The Undertaker Vs. Kane (the streak. Maybe even a 'gimmick' match. Buried Alive, Inferno)
Triple H Vs. Kevin Nash (no holds barred, no DQs etc. A Grudge match, providing Nash is able to do it).
Could be quite exciting actually. Yes Taker Vs. Kane has been done to death, but it could be billed as THE last one, no matter what. If Kane comes back masked, on a rampage, maybe they could bill it as The Undertaker coming back, putting his streak on the line, and having to 'stop' Kane. Obviously Taker wins, retires at 20-0.
All just ideas. Though, I got a fair few Survivor Series predictions wrong....so I'm more than likely way off!