I built something a while ago call bam[0] that basically did that. You specces your application in an xml file and it built out the admin ui, orm code, and db schema. I took a bet on a soon to be dead framework and ultimately didn't have time to continue the project, but it worked pretty well.
That makes sense. I'm hedging against dead technology by keeping the database and code generation parts separate from the templates. This way you can have templates for any languages so long as they speak a shared (HTTP) API specification.
