As reported earlier it appears that Josh Barnett has tested positive in a CSAC pre-fight screening and as such will be forced out of his fight on August 1 against Fedor Emelianenko.  The latest update on the situation from MMAWeekly gives more info on the current status of the situation:

Additional sources told MMAWeekly.com that while middleweight Belfort had agreed in principle to step up two weight classes to face Emelianenko, he had not yet fully committed to the fight and was weighing his options Tuesday evening. However, the search for a potential replacement for Belfort is also underway.

There are two important things to consider given the situation.  First being that you can expect Josh to never have another regulated fight in America.  This is his second positive drug test - the first coming during post-fight testing following his UFC Heavyweight Title win over Randy Couture in 2002.  I would think that one has to have significant doubts that Barnett has fought clean at any point since then as most of his fights were taking place in Japan outside of promotions with comprehensive drug testing policies.  He did fight twice in the U.S. for Affliction in 2008 and did not test dirty but at the very least he has established a pattern where in the biggest fights of his career where testing was present he returned a positive sample.

Now one has to wonder what this does for the future of Affliction fight promotions.  While there have been rumors that this would be the last event Affliction promoted there have also been rumors that some in the organization were confident that fight promotion would continue and that certain fighters were being offered extensions on their current contracts.  With this fight between the #1 and #2 ranked heavyweights in the world according to the SB Nation/USA Today Consensus Rankings being cancelled it represents a massive blow to Affliction's future promotional hopes.  To lose such a high profile fight on short notice will most likely lead to a drop in PPV buys which is something Affliction can't afford given the large contracts they are holding for their fighters.

Belfort as a replacement is far from an ideal situation.  He holds some name value from his time in the UFC but at the same time, he is a middleweight.  The best heavyweight in the world (and probably the history of the sport) facing a highly ranked guy who fights at 185 is a really tough sell.  Just ask Bodog about that one.

The other potential option being bounced around was Bobby Lashley.  Lashley represents some better name value from his time in the WWE, but he is also the guy who got about all he could handle from Jason Guida 4 months ago.  It's not really a competitive fight and it reporesents an almost unreal step up in competition for Lashely.

Many fans have been asking if Fabricio Werdum may be able to step in following Alistair Overeem's removal from the Strikeforce show on August 15.  While Werdum represents a heavyweight option who has been actively training he also represents a fighter who was knocked out in brutal fashion in his last fight.  What little name value he carried with the American audience was sent sailing into the rafters of Allstate Arena riding piggyback on his jawbone following a Junior Dos Santos uppercut.

We'll see if Affliction can pull a rabbit out of the hat with this one but this positive test by Barnett represents a serious blow to not only this show, but the promotion's entire future.

UPDATE 1:  MMA Fanhouse has the following from Atencio himself:

When asked if the August 1 MMA card was off, Atencio said only, "Him and Fedor is off."

Asked whether the Affliction: Trilogy card at the Honda Center in Anaheim was still going on as planned on August 1, Atencio answered, "At this point, yes."

Atencio gave a terse "no comment" when asked whether a Sherdog report that Vitor Belfort and Bobby Lashley were the two potential opponents for Fedor on August 1. He also declined to speculate on whether a deal could be worked out to have Fabricio Werdum, whose August 15 fight with Alistair Overeem was canceled yesterday, might be Fedor's opponent.

Affliction: Trilogy coverage