When it goes to leave the new version for former: 4.6 build 701?
I have no idea but you will see it announced on the forums when it is released, so you will get advance notice. The auto update will also catch it within 7 days of it being released, so there really is no need to be concerned.
I could be 695 since Alwil has tested that one internally.
But than again, they are now testing 7xx or something like that