After some speculation that this issue would arise a few weeks ago, it seems it may still be an issue.

Not once, but twice were the visas rejected from two of China's top teams who participate in the LPL.  Though the teams are not yet qualified, but every team that has a chance to go has already been sent out invitations.  While two players have received their visas from OMG, three are still afloat and Positive Energy has received none.

With China being arguably the second most powerful region, the time draws near where we have a significant problem in the Season 3 World Championships.  Should two of the top Chinese teams not have a chance to play, including OMG who has been overwhelmingly dominant in the LPL, Riot will have to either grant the teams that would play them a bye or reassemble plans altogether.

Source - igoodgame