i don't think an actual script is required, i think a system is required for developers to generally access. xenwss+snapshots makes sense. setting them up would be the task.
actually since this issue was created a lot has happened on the integration end where Eloy has been building many tests into Jenkins. Now, with a every push into integration.git, upgrade tests are run on jenkins. So upgrading regressions may not be such an issue now.
i think that we don't have within HQ, any accessible test/dev rigs for LDAP (network contention) [remove and insert different protocols that moodle supports].
at the same time i feel STABLE developers don't have access to many environments like mentioned above and some have some setups that duplicate but anre't shared easily. for example, i've got apusdbtest.moodle.local on which i'm running an mssql instance. I've also been creating databases and accounts on it when other developers ask me for one. i cannot/don't know about sharing out the oracle setup tho.
anyway thats the background. really, this issue was created as an idea for Tim when he just came aboard