I am under the impression that the advent of a globalized internet culture has fostered the nostalgic phenomenon. If you are a regular reader of any social websites where people can publish content you can see the extent of this among people from "Generation Y": clothes, old games ( Prince of Persia on Apple 2 anyone ?), actors, movies, music, etc... It doesn't even have to be good, it will be put on a pedestal anyway.
What enables us today is that these old things which use to be forgotten by previous generations can now be accessed at will: old videos are put on Youtube, old pictures are backed up everywhere, memories are slowly becoming immortal.
I am absolutely not a nostalgic person myself so I don't feel the impulsive to think about oldies but I think it's a very interesting thing to analyze, maybe it's even a bit worrying: Could these fond memories hold us back?