The reason SK-Test instance appeared is the same reason it's so unlikely to appear again - the production server died one weekend and we knew it would be down for at least a few hours, or at worst a day or so.
In order to give folks an outlet, we shared a URL to a test copy of the server where we could have fun in the meantime - there was no point trying to transfer the backups across to it (time required + added delay in transferring them back), so we made it a kind of free-for-all anarchy where imms tweaked and hacked and interacted. It was a great solution to a messy outage.
The current server, however, is much more protected against severe outages. Being a hosted solution means the internet connectivity is much more robust (and faster) and being a virtual image it can be moved between hardware as necessary should there be issues in that area.
Ah, memories.