An article in the UK's inSourced talks about the influential sites for 2003. Google is discussed first as a site so popular "it became a verb."
After talking about other sites listed in the Top Ten for the year (an interesting read), Blogger is singled out as the "least mainstream" but the most likely to become mainstream in 2004:
"Blogger is a tool that lets you publish your own ‘blog’, or web diary. The Blogger company was bought by Google last year, a sure sign that ‘blogging’ is moving further overground. Even if nobody you know has a blog now, in another year someone will. The significance of blogging is the way it allows communication on every level - politicians reach out to their public through their blogs, and the public ‘blog’ to share stories and pictures from their lives with friends. What’s next? The least mainstream of the sites on this list, Blogger is likely to move further into the limelight in 2004."