Poor ole' plaid gets a bad wrap, i.e. slutty schoolgirls, your grandmother's ridiculously overdone curtains, and who could forget, the Burberry-wearing prepsters. But, it's making a serious come back -- more urban cool and less Hot Topic-y.
Decades matter. Think about the 1950's versus the 1960's, for instance. That's how different one decade can be from another. Let's put the past behind us and think about how we'd like the next decade to be.
We must understand the changes from the last 10 years in order to anticipate the direction of our global economy for the next few years. I believe the zeitgeist is the Decade of Disillusionment, or the condition of having lost naive faith and trust.