Warhound isn't cancelled. Its been taken back to the drawing board after a week of mass beta. Big difference. Blizzard needs to add a new unit for Terran. You can bet your ass the Warhound will be back, but in a different form.
And since they start listening to the pro players feedback, and are asking for their opinion and what should they change, we might get the new, balanced and good Warhound that serves its purpose instead of being able to counter everything.