It's typical. Same people applauding Cain would've been the same people calling him overrated if he had lost. Like they did with Carwin.
Last nights loss still doesn't change the fact that..
1. Brock Lesnar is tied with Randy Couture and Tim Sylvia for most UFC HW Title defenses in a row (2 a piece)
AND
2. Brock Lesnar is the only HW in MMA history to ever defeat 3 top 5 opponents in a row (#3 Couture, #2 Mir II, #3/4 Carwin). And he stopped ALL of them. Fedor has never done that. Big Nog has never done that. Couture, Sylvia, Arlovski, etc. Only Brock.
So it's nothing new. Besides.. Brock lost to the #4 HW in the world. 4th top 5 opponent he faced in a row. Yet another thing no other HW has ever done (fight 4 top 5 HW's in a row).
Couture did it.