Well facebook make a change today with the "Like" button.

Quote:
Since it launched in April, the Like button has given you the opportunity to make your websites more social in just a few steps. Today, we’re releasing more features for the Like button to add even more value to your site.
  • Commenting for the iFrame version
  • Publishing to connected users via the Graph API
  • More robust analytics

Commenting Now Enabled with IFrame Version

Now, when a user adds a comment to the iFrame version of the Like button, a larger, more prominent story will be shared with the user’s friends. In the past, we’ve seen comments result in increased distribution and referral traffic. To enable this feature, ensure that you are using layout="standard" and the width of the button is at least 450 pixels. Take a look at this example.
Continued at: Adding More Features to the Like Button

So what's everyone think about this change?