In an interesting editorial about WordPress and wordpress.com, Ken Yarmosh of Techosight makes a great observation.
WordPress.com is going to bring a superb open source blogging platform to a much larger public audience but it will offer only a taste of what is possible. And that is why my hypothesis is that WordPress.com will actually be a gateway to WordPress. If there is any strategy behind WordPress.com, that may be it. Proud developers like Matt simply want users throughout the world to play with their software. More importantly, he wants them to help make it better.
I really believe that once people get a taste of what a WordPressMU driven site like wordpress.com can do, and they have the time and experise to move “out and up”, they will head straight for WordPress.org, the independently run WordPress, so they can tweak and fiddle around.