Unless of course Jake Shields beats GSP, this is the best fight available after GSP/Shields. Nick won't fight his teammate, but Nick is by far the most interesting option for the WelterWeight Title. GSP/Fitch 2, has zero buzz behind it, and there is little else out there right now for GSP.
Nick hasn't fought a wrestler in some time, and has been fighting guys who don't employ LNP. Nick is prone to being LNPed , evidence from his UFC days, and stylistically speaking, will always have a tough time against guys who LNP. It's quite possible that Nick entering the UFC will meet the same exact issues that Nate is going through. Beating nearly everyone else, but being held on the ground, and without the ability to scramble, and the wrestler being very cautious, it's nearly a lose/lose for Nick to jump into the UFC.
But this guy is by far the best WW outside of the UFC. We need to see this fight, as it is the most interesting, and the fact that WW has already been cleaned out. Without these scenarios in place, I would be fine with the status quo. Feeding GSP contenders, is the number one priority, regardless of prior arrangements, IE no co-promoting. This is a fight that can get a lot of hype behind it, and will be an easy sell obviously with the personality differences, and the champion vs champion logic...
Many will write Nick off, as that he will just be LNPed, but there is a reason why they fight. Nick Diaz has to be one of the toughest in WW, he is one of the best strikers in the division, has the heart of a champion, and brings it every single time, and with great cardio. GSP has never fought a guy as big , and as good as NIck is off his back. Penn is one of the best, but size does play a factor in grappling. Also, like I got into before, the options for GSP are next to nothing. With Anderson Silva lurking in the background, and only Fitch/Penn on the horizon, where else can GSP turn? GSP taking Nick Diaz would continue to give the WW division more time to produce up and coming contenders.
Nick is 6'1 and GSP is 5'10. Nick has much longer arms than GSP. Nick is going to be a big problem for GSP on the standup, honestly, I'm not sure if there is a WW in the world who can deal with Nick's overwhelming style. Either way, this is the fight that needs to come up next in the WW division. Also, Nick says he needs some time off, so this would be a good time for him to rest up before his Title Shot.
Obviously we have the whole co-promoting issue, but regardless, this fight should happen.