I doubt that anyone will come along that will be able to ultimately fill his shoes, as it were. A "supernatural" character in this day and age won't be taken seriously by a good number of fans because a lot of fans no longer are willing to suspend disbelief to that degree. What's most likely is that fans would crap all over the wrestler & character from the start without even remotely giving him a chance to show what he can do. It's part of why it's becoming more difficult for some wrestlers to get over than it was 15 to 20 years ago. During the mid to late 90s, however, fans were willing to embrace such a character even though they knew every bit then as now that it wasn't real, at least to a certain limit. After all, Papa Shango was an absolute joke and it's easy to see why. Not only was it an over the top, stereotypical parody of Voodoo and followers of it, it was just flat out hokey.
Also, you have to take into account that Taker himself was something of a physical rarity as well. A legit 6'8", 300 pound man who not only had a strong presence to go along with size & strength, but who also had a surprising amount of speed, agility and great cardiovascular conditioning who knew how to use psychology and his character to tell a story inside the ring. These days, a lot of fans automatically piss all over a wrestler who shows up on the WWE roster who happens to be significantly over 6'0" and 250+ pounds without giving him a chance. In WWE right now, probably the two top "big men" on the roster right now are Luke Harper & Erick Rowan and they're over as a tag team and as part of Bray Wyatt's "Family", but wait & see how many fans, especially internet fans, start to turn on them if either of them goes single down the line and gets himself a big push.
I don't mean to exaggerate, but there genuinely are a healthy sized number of fans that have what could almost be considered a prejudice against big guys. At the same time, however, it's true that a lot of big guys who come along generally wind up crappin' the big goose egg while the majority of the most promising talent to come up through the business in the past 10 years have been wrestlers who're well under the 240-250 pound mark.
Right now, if there's anyone that could potentially step into Taker's shoes with his sort of enigmatic, mysterious character, it's probably Bray Wyatt. While there's not really anything "supernatural" to his character, his magnetic personality does sort of give off that aura of the character being something "more than human" with all of cultish rants and proclamations. But I don't think there'll ever really be anyone like Taker in wrestling again who'll be taken seriously by a lot of fans.