Seven:
It will be fascinating to see in 100 years which teachings by the current Prophets are labeled as "opinion."
Harmony:
Most if not all of them. The current prophets' offerings of earrings, tattoos, and teased hair will likely not be at all applicable to life 100 years from now. Heck, they're not applicable to life now. Life left them behind 50 years ago. They're stuck in the 50's, and seem to think life is a 2 dimensional takeoff of Leave It to Beaver.
I agree with Harmony that the earring and tattoo ban, which TBMs took as gospel truths direct from God for about 3 years, will become merely opinion as soon as Gordon B. Hinckley dies.
Women will eventually be allowed to hold the priesthood, probably not for another 50 years or so, but when they do the apologists will claim that there never was an official ban on women holding the priesthood. It was merely the opinions of past prophets and it was never doctrine.
The Book of Abraham will quietly disappear from future editions of the Pearl of Great Price. When asked about it, the GAs will claim that Joseph Smith never intended it to be canonized and the First Presidency canonized it during a time of great persecution and their judgment was effected. It was never intended to be canonized, and if the saints had not been so harshly persecuted in the late 1800s, it never would have been.