Should Khan move UP in weight?

I know the boxers in the light welter division can punch noticeably harder than in the lightweights and with his chin it does not make a good combination, but would a move up benefit Khan? In my opinion the lightweight division is too stacked at the moment for Khan to make any real impact with his chin and his defence. If he moved up he would be moving into a relatively weak division, and would have a bigger chance of having any world success. His dramatic KO last night showed that his defence needs vast improvement to be anywhere near a world level fighter. But if he can improve his defence, and this is a big if, I still think he has a great future. Khan is a very skilled boxer, who has a lot of power, and a lot of speed. If he can get the defence and adapt to a new style, he would be a pretty frightening opponent. I went a bit overboard last night and stated Khan has no future, but that was more over the shock of seeing a guy who I have watched since the olympics, and seen everyone of his professional fights get KO'd. I still think he has a bright future if he can sort out his obvious problems. You can have a bad chin and a good defence, or you can have a good defence with a bad chin. You can't have both.