i believe that now all keys are known , it means you could technically make a cfw that could be installed on any ps3 ofw. however. its not really as simple as that. the keys only mean you can decrypt it all. it dont mean you will understand what your seing or even be able to find a flaw or weakness in it. (per console keys)
What it effectively means is now that it can all be decrypted there is the possibility that someone will find out how the fw and ps3 gos about the verification of per console keys etc. and then copy the process, and make a new cfw that will update on ofw above 3.55.
it don't mean it will happen , it just means it could be possible if someone is smart enough to work it out. or at least thats how i understood it, ive been wrong before though. what is more likely is. now you'll just get a 4.31 cfw that installs only on 3.55 or below.
I bet theres a hell of a lot of code to read for devs. look how many files theyve been given access too in just a few months. The PS3s life will have ended before anyone gets round to making cfw install above 3.55 ofw. I reckon the few people that probably could do it aint even working on it, (they have no need) and the rest wouldn't know where to start.
but like i say, I'm often wrong, and this is highly likely to be one of those times.