sign in with your Facebook or Google credentials. The change will go live tomorrow, January 20, and effectively hammers the death knell for Yahoo's continuing identity crisis.
Yahoo first rolled out a federated OpenID login to Flickr back in October, but Google was the only accepted third-party sign-in. With the upcoming change, you will be able to use Facebook and Google across all of Yahoo's Web properties -- which admittedly, after signing the death warrant of a bunch of its sites, is not a whole lot. Still, it means you'll be able to customize your Yahoo search experience, comment on Flickr photos, and play with the awesome Pipes RSS remixing service, all from the comfort of your Facebook sign-in.
Incidentally, you won't be able to use your Facebook or Google details to log into "desktop or mobile clients," which presumably means Yahoo Instant Messenger.