I was a bit surprised that a northern coyote, Kai Zheng You, got picked as Person of the Year :-).
Time picked "You" as Person of the Year, essentially making individually-created computer media, like blogs, YouTube and Wikipedia, the metastory of the year. Blogs have been around for a half-decade plus (2001/2 is when blogs showed up on most reader's radar), but MySpace broke onto MSM radar this year, as did YouTube.
Not everyone is Time's You. I'm You. Most of you in the Peanut Gallery are You, especially if you're writing your own blogs. My mom's not You, since she rarely ventures onto the Web.