WCG may have an expected problem. The USA has always had a cumbersome visa system and in today's highetened security environment this may become a problem for travelling cyber athletes. Several WCG cyber athletes from China, Russia and many other nations are already getting a taste of Homeland Security.Apparently WCG USA may have some new troubles, that to be honest do not surprise me. Several WCG qualifiers are having troubles obtaining visas to enter the USA. Chinese and Russian cyber athletes,
PJ and 
Androide to mention some, apparently are having problems obtaining visas to enter the USA, maybe even Korean cyber athletes too from the rumors I have read. 
Usually this is more of a problem with timing and having to overcome bureaucracy than actual obtaining for this event. That is why Preliminaries should be done and finished with many months in advance, especially when it comes to travel to the USA that is world expensive and renowned for its cumbersome visa system.
For a cyber athlete the best visa to apply for is the P-1 visa for internationally recognized athletes and entertainers and their essential support staff. If the application is made in a timely fashion with support of WCG this visa is not hard to obtain.
If you do not belong to one of the blacklisted nations obtaining a B1-2 visa, which is the tourist visa is probably the easiest route. You do however have to claim you are entering the country for the purpose of Tourism. Some nations you do not even need this and all you need is to fill out an application in the airplane called the “visa waiver” that allows you to stay 3 months in the USA as a tourist. You can find a list here. » Visa Waiver Program.
If the applicant has vision and is interested in staying longer in the USA in hopes of making a career out of pro-gaming in the USA, he could go for an O-1 visa that is reserved for persons of extraordinary ability in science, arts, education, business or athletics. This one is a little harder to pull off, but if you can submit proof of having won many international tournaments in your sport and have the support of WCG or your country's pertinent sport organization it is possible. Chess players have used this visa successfully to enter and stay in the USA almost indefinitely.
You can also apply for a Q1 visa which is used for exchange visitors coming to the USA to participate in international cultural-exchange programs if the WCG officials are smart enough.
The key factor for some of these visas is time. It would be very unfortunate if any WCG participant is not allowed to participate only due to visa problems. This is something WCG can solve and it is definitively something the US government must not allow to happen. WCG is a huge event geared to the world youth. It is a beautiful PR opportunity for any US government official or politician to grab a hold of if it becomes a problem and it hits the main stream media. Visas can be issued within one day if needed and can be waivered even faster for special cases at the discretion of the consular authority. I do not think anyone will have problems entering the USA to participate in WCG if he makes enough civilized noise.
My advice to anyone with problems, call a local government official or politician and ask them to call the US Consulate and explain the problem. This will give you a head start if you are late in your visa applications. WCG should really step in fast on this problem before it becomes a fiasco. If any participant does not participate in the event due to visa problem it is as much a WCG problem as it is a USA visa problem.
Still, just so I do not give the wrong impression, let me explain that I have travelled to (and lived in) over 26 nations in the course of my life and I know this sort of problems are by no means exclusive of the USA. Immigration and border officials love bureaucracy, it's in their blood and it is what gives them job security no matter what country to travel to, and trust me they will make you waste time, take your money and give you endless hours of frustration.
Links
Travel.state.gov - Visa Information
