Yes, Sky TV should conservatively be valued at $600M based on earnings. That would be a PE of only ~13 or ~8x FCF.
Right now $440M is only a PE of ~10 or ~6x FCF.
Add to this the injection of $50ish million from the property sale and the valuation seems even crazier.
Plenty of scope for the re-rate to continue...but it will go up gradually - kinda like what we saw with NZME (only even higher upside potential with Sky because price to underlying earnings has been way low for a long time in our case).