Blizzard already said "No" on that.
As for the Jaina novel, while Baine had a lot of development, all of it was mostly beside Vol'jin, who still acted like the more vocal anti-Garrosh leader. While I agree that's not entirely proof of him becoming Warchief, I think the fact his attempted assassination is going to be the first domino pushed, the fact he is getting his own novel, and the fact he is getting his own model in 5.1 to be pretty good factors that they want him to become more important down the line.
As for the people who say "The orcs would never be lead by anyone other then an orc!", you guys did play WC2, correct? The game in which two clans, the Twilight's Hammer and the Laughing Skull, both had
ogre chieftens at one point? Orcs do care about themselves more then other races in a general sense, but on the scale of respect, race is under strength/power. Or did anyone here actually think the whole Horde would have broken down if Cairne has won the duel with Garrosh?