WordPress.com launched recently, using the invite process popularized by Orkut and GMail to seed the service. Using WordPress MU, multi-user WordPress, WordPress.com looks to be competing directly with TypePad, Blogger, and other hosted blog offerings. I've never used any of those other services, so I can't compare or contrast any of them with WordPress.com.
But I can say that I am thoroughly impressed with what I've seen in WordPress.com so far. I'm still skeptical about the WYSIWYG editor, but I'm giving it the ol' college try. Theme selection is easy, and the bundled theme previews make it super easy to see what you're getting before committing. There are obviously still some bugs to work out, but WordPress.com shows a lot of promise.
And because you can't have too many blogs, you may also visit http://skippy.wordpress.com/.