Given Magic's large ensemble cast of planeswalkers, R&D tends to think it's prudent to rotate the spotlight every block so that everyone's favorite characters get plot time. One planeswalker who hasn't been heard from in a long while is Sarkhan, the dragonmaster nature mage and pawn of Bolas. The apparent Mongolian themes of the upcoming block plus Sarkhan's appearance and culture (what little we know of it) means many rumormongers are seeing his return in the cards.
When enfj-panda asked Mark Rosewater on his Tumblr blog, "How is Sarkhan doing these days? Is he collecting his marbles pretty well after he lost them?" Mark expressed a like for the character:
"Sarkhan's a fun character. I'm sure the creative team will bring him back at some point."
Chandra's starring role in Magic 2014 means she'll probably stick around as the monored planeswalker of another core set; but for diversity purposes it would be interesting to see a monored Sarkhan in a block one of whose sets is titled Dragons of Tarkir - it'd be almost criminal to leave a perfectly on-theme character out.