The bottom line is that while attractions like Shrek still exist, MiB and Mummy shouldn't even be considered going anywhere anytime soon.
While MiB has been maintained pretty well, The Mummy desperately needs a solid refurb. The screen/face room has been absolutely atrocious for well over a year now and there's simply no excuse for it.
This is one of the things that frustrates me about Universal. Rides like Spider-Man, Minions, the HP areas, etc are upkept in such a pristine manner- and then you get things like Dudley Do Right, Cat in the Hat and The Mummy where the rides and/or queues are deplorable.
Hell, walking through the Dudley queue, you might as well be at a Six Flags it's so filthy with trash over the railings- and it's been like that for years.