DBIC Deployment Handler
I think, after a load of floundering around, that the way to use DBIx::Class::DeploymentHandler has finally clicked - I have no idea why it seems to have been so hard for my mind to work out how to use it, but this module has really made my head hurt!
So, I am aiming to put together a few blog posts on using Deployment Handler to manage upgrades (and theoretically downgrades, but I have never tried those). I should get something produced around the end of next week (minor issues like stage managing a play in theatre all next week allowing!).