Im usually not one to spread rumours and I already updated my PS3 successfully to firmware v1.5, as I go online and its mandatory.
I've one issue with RFOM and have been monitoring the myresistance forums, there are several posts this evening of people bricking their PS3's with the Version 1.5 update that was released to NA today.
Im unsure at this point if these are real issues or if they are compounded by people having connectivity issues while doing upgrades, or turning of their systems while doing the upgrade however it may be worthwhile staying away from the update for a day or so to ensure that its actually not a problem with the update itself, im sure if it is an issue it will be pulled or fixed ASAP by sony.
This means that youll need to stay offline during your wait as it will prompt you for an update to go online.
Again my update worked perfectly but there are reports on other forums of the update blowing up PS3s.
cheers