Not much, that was one of my focuses in the current release as we needed to deploy a sinatra app. I think the only thing that missed the release was generating a Rakefile into the project root for non-rails projects. Here's what ours looks like: http://gist.github.com/189256

Ping me on the rubber mailing list if you have any questions - I'd be interested in hearing how this works out for a non-rails app for someone other than myself :)