I've never really liked the idea of renovating Fenway so much. Hell, I don't like the monster seats. But if something needs to be done, renovation is the way to go, not building a new park. Fenway is the sox, and it is perhaps their main draw. If the sox suck, Fenway will still draw the fans in.
A park like this:
http://www.ballparks.com/baseball/american/bosbpk01.jpg
Would suck. It seems so impersonal. I dont care about amenities and such, I want a great baseball experience.