I can forsee Bravo and Virgin1 going, along with Sky Real Lives being subsumed by Living. Challenge is a fairly unique offering however and, though their website is looking worse for wear, their forums remain quite active with regular replies from channel staff.
I reckon the only channel to go will be Virgin1, which is after all mainly a channel to show their own programmes on Freeview (as was FTN). The few exclusive programmes it has will probably move to Sky1/2/3 if they're any good.
I can't see Living being touched too much, it's a good brand and very popular, it certainly doesn't have much overlap with Real Lives.