I hope it does BUT I don't think it will happen. The 900 was never hacked, they couldn't get it done and have long since gave up trying. I'd be shocked if Nokia wouldn't put the same type of security in the 920, knowing the 900 was basically unhackable.
I love custom roms and when phones get hacked. Like it or not, devs always seem to give us more from our phone than MS or the phone maker has. I had a Trophy and custom Roms and apps that weren't possible through the market place, made my Trophy a more tolerable phone to have for over a year.