Phusion released Mod_Rails and a gem called Passenger today. I watched the screencast and was a little blown away at how easy it was to deploy a rails app. The most gorgeous part is because its hosted in Apache you can run other nice modules like Mod_Security, without having to use an additional transparent proxy. There are some benchmarks out, and it looks like Passenger edges out Mongrel in most tests. This is very exciting news indeed.
Hopefully I can get some benchmarks out sometime soon!