'Taker could easily work a schedule similar to Hogan's and use his annual match for Mania for years, if he felt so inclined.
Right now, as it stands, WWE doesn't have anybody who is worth the rub or important enough that really needs it.
It's one thing to have obvious main event charisma and persona but it would also require for the company to have complete faith in that worker to pull the trigger.
In 2005, Orton was still the WWE's golden boy and even there he couldn't sell himself enough to knock Taker's streak.
You could take a guy like CM Punk, for instance who is probably worth the rub in that he would be capable of making it mean something and does have the main event persona neccesary for that but it would take complete backing from WWE to do this.