The bad thing about Rocky coming back is... people will see the current product, judge it against The Rock... and when he leaves, people will crap over the current product and turn away in droves.
I mean, there's guys like Punk, Miz, Cena, Taker, HHH that would fit in any era... but a lot of the guys just aren't going to cut it after fans get a taste of 'what used to be'.