This is something that everybody saw coming, but it's worth noting anyway - Nick Diaz has been levied a temporary suspension from competition in Nevada following a positive test for marijuana. The positive test came after his fight with Carlos Condit at UFC 143: Diaz vs. Condit, and now it's pretty clear there won't be a rematch any time soon. Diaz' post-fight antics included retiring and suggesting that Condit fighting to his gameplan was cheap.
Either way, the Nevada State Athletic Commission voted unanimously to suspend Diaz until an official disciplinary hearing later on in 2012, likely for April. At that point, Diaz can argue his case as to why he doesn't deserve a full suspension and the revocation of his license to fight. As noted earlier, Diaz could have applied for a medical exemption for his marijuana, which he uses medically under California state law. He did not apply for the exemption.
Diaz will have to provide plenty of information to the commission in advance of his official hearing on top of his, you know, defense. He'll need to provide information regarding his medical usage in California, will have to provide information about his purse and bonuses, and he'll need to talk about the last time this happened, back in 2007.
As previously noted, it's easy to imagine potential complications with a hearing. Diaz probably didn't really plan on going through with his retirement, but the fact that he'll have to go through all kinds of things which surely don't make sense to him (he chooses to deem things he doesn't like as "not making sense") makes it all seem unlikely. Well, perhaps unlikely isn't the right word, but it certainly can't help things, that's for sure.