That's a great question! Ive been wondering it myself, but 3.42 is in the past the new update is 3.50 we need to start asking is 3.50 going to be hacked and all future updates? Sony managed to have the ps3 for 4 years without a backup hack and now a hole was found, whether this hole can be fixed by Sony with updates is hearsay. Just take it one day at a time and see what the hackers come up with I guess.
When 3.50 is hacked, it will probably be an unsigned firmware that will only install on a jailbroken 3.41 system. Time may bring the ability to flash such hacked firmwares from later firmwares, but I wouldn't count on it.
Yeah right now I really don't see how it would be possible to have the dongle upgrade to work with a newer firmware if the update disables the hole that the jailbreak uses. But i guess there maybe still a way around since sony still needs to get some repaired consoles to debug mode. We been waiting to see an update for the back up manager alone and have yet to see that happen. Only time will tell, we just need to play the waiting game.