Does Champagne get better with age? Is aged Champagne better?
The answer is a qualified yes. Almost all Champagnes, even simple Non Vintage varieties, benefit from 6-12 months. Many prestige Champagnes, for example Dom Perignon from a great year, or Vintage Krug, or Salon, not only get better as they age but are often way too young when released! For example, Krug 1996 when it was released was fairly unpleasant to drink as was the 1996 Salon. It's 2012 now and I'm STILL not touching them!
Now most Champagne producers, certainly all the big houses, will tell you their wine is ready to drink when it is released. Often they will claim there is no reason at all to age it. Then again, they are in the business of selling Champagne and in general requires for Champagne to be drunk.
All the requisite material for a great Champagne is there -- but it still needs quite a few years to mellow and come together, and it comes together far better in big bottles. I even age some non-vintage magnums for a few years, for example I've got a few mags of non-vintage Moet and Chandon White Label stashed away for perhaps 2-5 years.