The Verge has the details of 500px launching a $19.95 image hosting plan to compete with Flickr Pro.
I think this is a good step, 500px is an excellent site and they need to be able to make more money to make the site better. Personally I agree with Thomas Hawk on Flickr being dead, but even dead they have a lot of momentum and name recognition on the web.
You of course can check out my 500px portfolio or all my images on 500px.