Like others, I use Facebook for photos I want to share with friends and Flickr as a portfolio. Having said that, I think Facebook has a much better interface (why does Flickr still insist my photos need a title?) and having this option is good.

It would be nice to see Facebook improve the quality of standard photos too. They're generally noisy as hell and have rubbish compression artifacts. Compare Facebook: http://bit.ly/bT1bjA and Flickr: http://bit.ly/c0a0FO