Dota 2 recently held its largest tournament of the year boasting a prize pool of over $18 million. Viewership totals are still coming in, but looking across the various livestreams confirmed millions of viewers. With all that success, Valve has told IGN that they aren't sure about Counter-Strike: Global Offensive having its own similar tournament.
Erik Johnson of Valve didn't rule it out either though:
We’re pretty comfortable with different projects taking different approaches to solve similar problems. As a company we actually learn more when we do that. If we all point everything in the same direction, we’d have a real blind spot for when we’re screwing up. In some ways, you want to diversify a bunch of decisions across different projects because you zero in on the right answer quickly, as opposed to 'we have this thing that’s working, everybody do that right now.'"That's the reason we won't see a torunament hosted by Valve for CS:GO, their second most popular game, but you never know. As Erik said, Valve looks for "different projects taking different approaches to solve similar problems." What that means for CS:GO is unclear, but a Valve-led tournament isn't out of the question. Regardless, the quote is Erik's acknowledge on the need for some solution in the eSports area of CS:GO so Valve will indeed be doing something.
IGN says that Valve's primary focus is on Dota 2 Reborn and getting that out of beta, placing the game fully in Source 2. Erik also said to expect Counter-Strike on Source 2 at some point in the future but gave no indication when that will be or whether it is something even being worked on at this point.
While Valve is focusing on Dota 2 at the moment, Counter-Strike has been steadily increasing in popularity so don't expect it to sit idly on the sidelines for too long.