If you have something to say, then a blog offers a cheap, easy global medium in which to express yourself. This is as true now as it was three years ago, regardless of what the groovy cats in Silicon Valley may be up to.
I write something, I post it, it gets read, hopefully good things happen as a result, somewhere on this small blue planet of ours. Unlike a book or a movie or a TV commercial, there's no waiting around for somebody else to greenlight it. The only light is the greenlight.
Sure, I hear you saying, "But the scale is so small." I don't know about that. At last count [and this was a couple of years ago] the "How To Be Creative" page had been downloaded a quarter of a million times. And Lord knows how many copies of the "ChangeThis" PDF version were printed out and circulated. Most hardbacks are lucky if they sell three thousand copies.
I guess my point is, if you're one of these people considering giving up on blogging in exchange for paying more attention to Facebook, Twitter, YouTube and MySpace, or whatever they throw at us mere mortals, bear in mind you are giving up on something rather unique and wonderful.