Last night, Yahoo announced that they opened up Yahoo Buzz to the whole web. When Yahoo launched Yahoo Buzz, it was only open to less than 500 or so publishers, for users to use. Now, Yahoo has opened it to any web page on the internet, allowing any of their users to submit and buzz up any content on the web. You can read more of the news at Techmeme.
We have been a Yahoo Buzz publisher for a while, so you have been able to see the Yahoo Buzz buttons on the bottom of our posts for a while now.
A WebmasterWorld thread does point out that it is "Restricted to US only." But other than that, there is not much discussion around this Digg-like service.
Forum discussion at WebmasterWorld.