Why can't you set up a virtual server with your default setting and applications and then clone it? (I'm really asking for more details, not making a suggestion in the form of a question.) You also get little benefits like having your .vimrc and ssh keys copied over.

That's pretty much what I do, and I wouldn't want to have to maintain an additional "personal heroku server" that would automate the deployments in the way you're talking about.