Pete and I worked on our deployment script last night. In the early days of our project, we thought we'd use Capistrano. Make no mistake, it is a great tool (I took it for a spin).
But when you are using JRuby, its a bit overkill.
I'm fairly new to the Ruby world, but I know the other deployment options for Ruby. They aren't awful, but they take a bit of work & have some moving parts to them.
A lot more work than handing over a .war file with a configured # of run-times to run within the JVM, a database script, and a runbook anyway. That in and of itself is compelling.
Oh yeah, you have to also run:
$apache-tomcat-6.0.14$ bin/startup.sh
(that's the runbook)