Mongrel2 may be enjoying some popularity because Zed wrote it, but Zed isn't a celebrity for no reason. Mongrel was a pretty damn good idea. He's also written interesting articles on his design decisions to come this far, and explained himself quite thoroughly. I think a lot of the HN community is eager to see where this goes.

Nothing is a solved problem in this industry. Look at the way the web has changed in the last 5 years. I think it's time to take a good hard look at what we use webservers for, and admit that Apache doesn't support a lot of common use cases very well.