Indeed, I know Diaz likes to bring a fight against anyone. GSP however, has a knack of taking the "fight" out of fighters.
Kos, Hardy, Alves, Fitch, Penn, Shields, all tough competition and aggressive fighters in their own right. All looked scared to engage with GSP and when they did he either nullified their attack or routed them in some way. He's too well rounded, too technical for Diaz I think.
Unfortunately this is the only fight fans want to see other than Silva which most likely won't happen.