Not exactly, but I am working on mirroring some of my stuff from flickr to 500px. Eventually I will find a piece of software that will allow me to magically post to both platforms. I have a nice circle of friends on flickr and I can't just pick up and dump them. I'm still trying to get used to navigating photo streams. I'm used the sequential flow of the streams in flickr, so I get confused sometimes when all I want to do is go from most recent to old, or vice versa.
Anyway, that's all I have to say about that.