When I first started getting into coffee a lot I thought that freshness was everything, I felt that if coffee was approaching 7-9 days old I might as well just ignore it and pass it off as bad. But really coffee will evolve and develop different flavors all the way up to 11-14 days. Anyways. Beer obsession came second to coffee for me, and I have a soft spot for super fresh (I)PA's. Is there anyone out there with a very developed hop palate able to determine if these super fresh hoppy beers develop like coffee? Or is it true that a 1 day old IPA will ALWAYS be better than a 5 day old IPA?
Matured beers are different from the same ones fresh. Whether they are better or worse is simply a matter of individual preference. This might be of interest , it refers to a traditional English IPA but then IPA was always intended to be aged http://zythophile.wordpress.com/2009/11/06/aged-white-shield/
I don't have a super sophisticated palate, but I would reason that it really depends on the specific beer. Something like Pliny the Elder has an extremely plain grain bill with almost no malt back-bone to speak of. The brilliance of this is that it lets the hop flavor shine through, but it will only get worse with age (and yes I've actually had old PtE; it sucks). However, something like Drake's Deongginizer has a massive malt back-bone. While the hop flavor will fade with time, I don't believe that the beer will "go bad" because it will always have that strong flavor base. It will just start to taste less like a DIPA and more like something else.