Things should start heating up pretty quickly now. The U.S. Marathon Trials are in less than two weeks, and the indoor season will be going strong by the end of the month. So we’ll be full gear into the buildup for London in just a few weeks. Of course one of the big questions in any Olympic year is: who will the major players. It might be a bit early to start identifying major players, but here are some matchups that I think bear looking for this year, that should have a major effect on medal distribution in London.   Usain Bolt v Tyson Gay v Yohan Blake (Sprints) These…