I'll admit I'm no insider and not one for quick news updates, as I have no idea what's real out there and what isn't, but in investigating the 2/21/11 situation from last night, I came across these links:
and then this one:
For those who don't feel like clicking away, I'll give you the gist.
The WWE Raw on the 21st is the one right after Elimination Chamber. The links above take you to the advertisement and a sort of program about what to expect at the Raw taping, and it lists "The Return of the Undertaker."
I suppose Undertaker AND Sting could appear in the same building. Maybe Vince and creative want to see the two of them have a staredown to assess what kind of legs such a match at Wrestlemania would provide. That doesn't seem likely, though.
It doesn't say anywhere in the link that Sting is involved in any way, but then again, this could have been written up way in advance, possibly before Undertaker was injured, and instead of Undertaker appearing, Sting will instead? I don't know how likely that is either...
I just didn't want to sit on this one. If anyone can debunk this, feel free.
In case this is true, though, sorry for crushing everyone's dreams. Believe me, if it is true and we don't get Sting, I'm kind of crushed as well.