I dissagree, i see Bisping defend the belt one more time no matter who he fights. Don't know if he will defend it more than that because as you said Yoel romero, weidman, rockhold, jacare... bad ass dudes. The confident in this guy has never been at the lower side but today his confident is higher than Tony Montana. A fighter who has done very well 3-5 rounds against guys like Chael Sonnen, Dan Henderson and Anderson Silva is a feard fighter, plus it lookes like he is at his best right now.
I think Weidman will give him the toughest fight of all the guys you pointed out.