While I agree that it's not important for long-running applications, there is still a lot of scripting done in Ruby, and it's very frustrating to get a a 5-to-1

While I agree that it's not important for long-running applications, there is still a lot of scripting done in Ruby, and it's very frustrating to get a a 5-to-10 second wait just to tell someone their arguments were invalid. Waiting that long for tests is also such a drag on iteration. I think once JRuby has stabilized the native gem support and has some sort of Passenger-like deployment option (Glassfish and Warbler isn't quite there yet), we'll see some big players built on MRI start to move their Web applications to the platform.