It's probably a completely different site, behind a separate VIP on an F5. I suspect they will just cut-over and you won't see any changes until they do the cut-over.
As far as time, if it were me doing the cut-over, I would do it either at midnight tonight (EST) or early in the morning, I would not do it during market hours :)
As far as testing goes, functionally the site is not much to test, the player is a mature, load tested product, the back-end to my knowledge is the 1and1 cloud computing platform, so really what we are looking at is a UI cut-over, should not be too complex and they should get it done early.
My .02