Google Buzz is impressive in that it attempts to link together so many Internet services, and there will be more added in the near future.
Friendfeed (now owned by Facebook) attempted to do the same but Friendfeed suffered from a perception that it was mainly for the geek elite.
Google Buzz and Friendfeed can be viewed as attempts to create a 'one ring to link them all' model that many other businesses are also shooting for. If you can own that ring, you rule them all.
You can see that strategy at Facebook, Twitter... and at other companies in their fields, such as Salesforce.com in enterprise apps.
Owning instead of linking...
Google has an advantage in that it owns many web services such as email, photo sharing, document sharing, voice calls, text messaging, maps, news readers, etc.
Facebook is also trying to become the 'one ring to link them all.' And like Google, it has its own services; it is about to launch a new souped up email system; it integrates Twitter updates; it has become one of the largest photo and video sharing sites; it has event services, and more services are on their way.
Microsoft Live has a similar strategy and similar services. And other companies are moving in the same direction, for example Nokia, with its OVI push around mobile maps, and other online services.
It will be important to own your own Internet services because third party services will undoubtably start to limit how much of their user data they are willing to share with other businesses. Such data is made available through open APIs (application programming interfaces). Open APIs are essential for social networking and sharing across many different Internet sites.
Increased competition will very likely be reflected in constraints on open APIs. Why make it easier for another business to roll up your user data? Each business will try to make life difficult for its competitors, and for future ones.
From open APIs to ajar...
APIs will become 'ajar' in that they will be partially open. Limited APIs are hated by the geek community but they make perfect sense for businesses trying to stop competitors from profiting from their user communities.
Limited APIs will make it very difficult for Google, or any other company, to create a 'one ring to link them all' model. We are much more likely to have a series of separate 'rings,' each one representing a fairly closed, self-contained world, where common Internet services are aggregated.
Unfortunately, this all points to a future Internet that is increasingly closed and proprietary.