This is probably one of the few times I'll agree with LyotoLeigon, and you never really addressed his point.
Silva has fought at 205 and done just fine, GSP has never fought above 170, and is quite a bit smaller than Silva.
He has never went above 170 because he doesn't care to take a chance. He could easily make 185 if he allowed himself to get fat like Anderson. Yea, Anderson makes 205 with ease...because he is a fat version of himself.
Anderson has been at 168, 175, 185, 205. GSP has never had a fight outside of 170...up or down.
You all are crazy if you believe Dana is just making fights. If you guys really don't think behind closed doors GSP has said he would do that fight. Of course Dana and GSP have talked about it. Probably while GSP was out. GSP knows this. He knows that is his next fight...and he has probably has verbally agreed to it.