It's possible the Blizzard RTS team could take another look at Warcraft, but only after StarCraft II: Legacy of the Void is finalized. There hasn't been official confirmation by Blizzard, but it looks like the game studio hasn't fully closed the door to future Warcraft RTS action in the future.
"This isn't the end of StarCraft, but it's end of this story for these characters," said Tim Morten, producer of StarCraft II: Legacy of the Void, in a statement to IGN. "We don't have any specific plans, but I'll say that the universe has so much potential for more stories, clearly other stories could be told."
Blizzard has never been in a huge rush to release games, and moves at its own pace - in an effort to create a gaming experience that players will fully embrace.
"It's very rewarding for us to hear that there's demand out there for more RTS content in the Warcraft universe so once we're done with Void I think we'll get together as a team and talk about what would inspire us to work on next. There's no question, though, that we'll consider Warcraft, StarCraft, or even new ideas. Anything is possible."