I just hope Romney has the courage to turn Ryan loose, and the campaign does not try to throttle him back to Romney-wuss-mode, like McCain tried to do with Palin.
Unlike McCain & Palin, RR have known each other personally for quite a while and went out campaign together long before Ryan was picked as VP. Palin was chosen partly because she's a female (flame me if you want, but you know it's true) and might have 'balanced' the ticket, in addition to conservative firebrand (albeit unknown then). I didn't see personal chemistry between the two beyond the campaign business. At most it's like a senior guy and his protege, not his equal partner.
I believe Ryan will play more role in the campaign than Palin did.