Right off the top of my head...
9/11, 8 Years of Cheney (Bush was just his puppet), Emo fad, Indie fad, Scene fad, the beginning of the Great Recession, iPods, Facebook, Myspace, Twitter, smaller cellphones, blackberries, iphones, Obama's election victory, Pluto no longer considered a planet of the solar system, Youtube, USB drives, higher internet usage than the 1990s, Space Shuttle Columbia disaster, first space tourist, first privately funded spaceflight, polo shirts, World of Warcraft, Guitar Hero...
And then there's the celebrity deaths: Michael Jackson, Farrah Fawcett, Ted Kennedy, Saddam Hussein, George Harrison, Chuck Jones, Fred Rogers (from "Mister Roger's Neighborhood") George Carlin...
Once again, this is all I can come up with for now.