Microsoft Photography & Video Blog:
I’m thrilled to announce that we’ve added the option to publish your photos on Flickr in the latest beta refresh version available today via Microsoft Update! In fact, Windows Live Photo Gallery has received the stamp of approval from the super cool people at Flickr as a first-class application for uploading your photos to your Flickr account! You can find the new option on the Publish menu. I’ll be blogging more about the feature details very soon so check back here for lots more information. Check out the press release here.
Neat. Based on the way this is implemented--via a right-click sub-menu under "Under Services"--I assume other services will also be added in the future. In particular, I'd like to see support for Google's PicasaWeb, selfishly because that's what I use. :)