Blizzard has announced that they are ending new content development for Warcraft Rumble. The game will continue to be supported with in-game events and bug fixes, but no new content will be added according to Blizzard News. This decision was made after careful consideration.
Collect the new playable Leader, Sylvanas Windrunner, during Season 1 of Warcraft Rumble beginning October 28 from the Guild Warchest and through PvP as a reward.