I have to admit I'm intrigued, but at the same time I'm really wishing it was a proper mod_rack instead of a mod_rails. Rack, for those who don't know, is the Ruby equivalent to Python's WSGI. A number of other Ruby web frameworks are built on Rack, including Merb, Ramaze, Sinatra and Waves.
That said, I'm still pretty excited and the numbers are promising. Wonder how well it handles long-running requests (which is Thin's problem, currently)
I am very interested to see the memory usage. With mod_perl, you pre-loaded a lot of your modules in the httpd.conf file, and Apache loads them once and shares them across all processes saving memory. With Rails that could give large memory savings, and memory is the major pain point of getting more than one or two Rails apps up and running on the same server as I understand it.
That said, I'm still pretty excited and the numbers are promising. Wonder how well it handles long-running requests (which is Thin's problem, currently)