Some theorists are saying that aircraft carriers wouldn't survive for very long in a modern war. Expensive, pretty, and doomed
http://en.wikipedia.org/wiki/Millennium_Challenge_2002
The fact remains that the most useful task a CVBG can accomplish is power projection - designed to avoid war through intimidation. And, to be fair, CVBG's are fairly intimidating.
However, if the carrier battle group is proved to be as vulnerable as some believe it to be, I can't see it's power projection abilities being very effective.