Now that Christmas is over and R&D is still on vacation, Mark Rosewater has plenty of time to relax, enjoy the downtime with his family... and answer all the questions that inquiring Magic minds want to know on his Tumblr blog. One of the most enduring Blogatog topics ever has been the Storm Scale - the rating of a keyword's likelihood to be seen again, from 1 being inevitable to 10, storm's own position, being "only if R&D gets hit by a bus." He was recently asked about two well-loved creature activated abilities - and gave surprising answers.
When karradur asked, "Level up on the Storm Scale? It's a personal favorite of mine. (The card frame also reminds me of Jello 1-2-3, which I know YOU'LL remember.)" he said:
Level-up is a 7. It has all sorts of issues but I could see us using it if it perfectly fit a design needed to capture the world.
While the new frame templating for level up may have turned some people off, it was also the best-received of Rise of the Eldrazi's keywords at the time - and seemed to derive its problems from being in a set that was so divisive. It seems to work with the adventure-world setting well and to be grokkable, so it's difficult to imagine it never being used again.
Meanwhile, when duality6265 asked, "Where is unearth on the storm scale?"
Unearth is a 4. I believe there is a good chance we’ll do it again.
Unearth's major problem seemed to be the stricture of being stuck in Grixis, an Alaran subplane that included blue mana, and thus being in a vaguely inappropriate color (in fact, blue seems to be the least likely color it fits in) - in a new world, it wouldn't have that issue. Plus, since flashback is so likely to come back, and unearth is just creature flashback, it logically follows that unearth is a good candidate.