“This is a fight that [Diaz] wanted, he really wanted this fight bad. And Georges St. Pierre called him out. He’s getting it. I expect Diaz to be there. Nick Diaz does not return my calls or texts. Nothing. It’s Nick Diaz. He doesn’t have to call me, he doesn’t have to text me; but, he needs to show up to the press conference. I would be blown away if he did it twice. It just would not be a good move. The thing about Nick Diaz is that Nick Diaz shows up for fights.
Source: Dana White: Nick Diaz Doesn’t Return My Calls Or Texts | UFC NEWS MMA News | Mixed Martial Arts | UFC News | BJPenn | MMA Fight | UFC Fights

It's all speculation, and Diaz 'not returning calls' is not the same thing as 'Diaz will not be turning up to the press conference', but it's got to make the UFC brass a little nervous.

I don't see Diaz wasting this opportunity again, what do you guys think?