It has not been implemented just yet. We are still working out the crew numbers, though I believe the actual details on how it will work are near completion. Most likely once its all ready there will be a week or so (maybe more) warning period before its introduced so you can get ready to stock up on crew when it comes out.
In the meantime, getting surplus ships docked in facilities or stations (I think) will mean that you will not have to worry about them degrading with no crew.
Really? Hmm, the last I checked with that thread they were going to decay or something - seemed kinda pointless to have crew if not having any didn't have an effect. But as with anything here, things can change quite a bit up until the feature is released, and even then they occasionally change after release.