I still think the effort WWE put in to get Sting into WWE, will out-weigh what they end up gaining from his involvement.Well that raises a couple of issues:
1) It seems likely that this will be one match for Sting. I've no doubt that the aura and mystery around it will compensate for any shortcomings due to his age. Still, I accept if that is not enough for some people
2) If we agree with your prediction that people will say he didn't live up to the hype, it still has the potential to bring more people to the product. Granted, the product is far from its best at the moment - but that is not to say it isn't enough to get some people back into it. I know for me, personally, it was the Rock returning that dragged me back in, and I have more or less stayed with the product since.
Essentially, Sting drives interest. Even people who haven't watched him before will be intrigued and this has a potential spillover. It's what the WWE, not Sting, does with this that is most important.
I just have no interest in 'Marking-Out' to a 55 Year Old wrestler that was in his prime 20 years ago.
Some fans seem to have this respect for Sting for never coming across and having a career in WWE. Perhaps its foolish on his part... if a wrestler has to get back in the ring at 55 years old, its somewhat safe to assume that he hasn't earned well over the years.
...and in a previous post, someone said, 'Look what Sting has done to get rid of The Authority'.... Sting did nothing, he honoured a contract and turned up at St.Louis.