I just hope the Silva v GSP fight actually happens, these 2 guys really are at the top of their weight class. I really don't want to see GSP take on Fitch or BJ Penn provided he beats Shields.
I think if GSP moves up to 185 he will have a harder time because at 175 he uses his size and athleticism to out-muscle guys and take them down at will. This has always been a big part of his game plan and tactic to winning fights which are mostly by decision. However, if GSP can take Silva down at will then Silva will have his hands full and it will be a tough fight.
Silva is technically brilliant, he has pin-point accuracy and precision with his shots meaning his size rarely seems to come into play. I love watching his style because he breaks opponents down mentally by ducking and weaving everything they throw and returning shots that land every single time. He looks like he's always cruising in 2nd or 3rd gear and he has a few more up his sleeve. The Sonnen fight really tested him but he had a rib injury and Sonnen later tested positive for roids so take what you want from it. GSP seems to grind out his decisions with a lot of wrestling and superior cardio but doesn't really have that KO power that Silva posses so it's a very interesting match up.
I would have to give it to Silva but it wouldn't surprise me if the fight went either way. I really think Silva can KO anyone at 185/205 and if he finishes GSP, it should silence all the haters.