Axel Alonso has been named as the new editor-in-chief at Marvel Comics, in a restructure that apparently enables Joe Quesada to drop the position and concentrate on his broad role as Chief Creative Officer of Marvel Entertainment (which involves movies, TV, digital, as well as publishing). In recent times, Alonso has been the Executive Editor at Marvel with responsibility for the X-Men/mutantdom, but he has far deeper roots in comics and in editing more generally.
On his watch, and before, the X-Men line has been going through interesting times (and controversial ones, though I generally approve). The current political situation within the X-world is fascinating if you're a long-time reader and not too invested in the original status quo, and I'll be fascinated to see how its potential is developed from here.
[Digression for X-aficianodos: We now have most of the world's mutants, including some of the villains, holed up on an island (which they call Utopia) off the coast of San Francisco. Scott Summers is in charge, making him effectively the ruler of a small, but powerful, nation; and some very unexpected characters (if you view the scenario historically) have become his chief barons. Namor (the Submariner) has built a new Atlantis beneath the island for his undersea people, as the result of a deal with Magneto, who originally created the island as one of his asteroid bases back in the day and briefly took charge of the problems confronting Utopia when Scott was indisposed at one point. Magneto has, nonetheless, sworn fealty to Scott and is still loyal so far. Scott is still an item with Emma Frost. Namor, Magneto, and Emma - all of whom have been villains in the past to various extents, and none of whom are especially nice people - now have the most influence on how Scott runs things. In effect, the four of them provide Utopia's core executive team. Professor X himself is somewhat on the outer, after making some questionable decisions, though he and some other long-standing X-Men still have places at the leadership table.]
It will be interesting to see if Alonso's promotion causes any particular shake-up to Marvel's overall content, though I really have no idea how likely that is. It's also not clear (to me) whether he will continue to have a special focus on the X-world or whether someone else will need to step up to fill that role.
Edit: I see that Tom Brevoort also gets a promotion in this restructure of top editorial positions. I'm still trying to get my head around who exactly fits where now.