The day we have all equally hoped for and dreaded is come to pass: Etherpad Lite has now replaced Etherpad "Classic" in production, and the labs instance is on its way out.
This is my as-wide-as-possible email warning to say that everything on the labs instance, as really should have been expected, is going to be gone soon. Not immediately - we intend to give you two weeks to get your important data off the instance and onto the new one at https://etherpad.wikimedia.org/ - but you should _absolutely_ be moving things as soon as possible. We will also keep a data dump around, in case anything else needs to get pulled out of the pads, but I would suggest not relying on that if you don't have to.
And in the future: If a URL has "wmflabs.org" in it...don't put anything, ANYTHING, important there. The purpose of labs is to let us experiment with new technology without having to worry about reliability.
Thanks so much for your help and understanding in the course of this migration.
tl;dr: http://etherpad.wmflabs.org is going down in 2 weeks, get yer stuff off it.