Gravatar toggle not showing up in settings in 2.5

I just successfully updated to 2.5, and attempted to turn on Gravatar via the settings -> reading tab, as specified in the documentation, but there isn’t anything there related to gravatars. I have gone through all the settings and so forth, but it isn’t on any of the settings tabs or in the user editors.

So I redeleted wp-admin and wp-includes just incase it didn’t upload correctly, and reuploaded them, same issue.

Then I cleared my cache and tried from a different browser, same issue.

Any ideas?

Thanks! Steven