The Washington Monthlyoffers a post-mortem for Culture11, which, roughly, was an attempt at a conservative version of Slate.
I think the site needed more time to develop an identity. The writing was uneven, and unfortunately, the highest-trafficked parts of the site (the “Ladyblog,” for example) also hosted some of its weakest material. (Note to friends of mine who posted at Ladyblog: Not you, of course!)
That said, I very much enjoyed reading people like Conor Friedersdorf, Peter Suderman, and James Poulos (among others). And for that, I’m sorry the site is gone.