S0ny have not allowed you to do anything, all the firmware from 1.00 to 1.54 are the exact same file whichever region you downloaded it from, the difference happens when the firmware is extracted and installed.
You can check this out by downloading the files from different regions and doing a MD5 checksum on each file, you will find the checksum is the same, this was/is exactly the same for the PSP.
I have two questions for those who have upgraded their japanese consoles using the US firmware. I plan to do the same, but I'm stuck right now as I've upgraded already to v.1.54, I'll have to wait until they release a new version.
1) After the upgrade do you have the O and the X buttons working back as in the US consoles (not reversed as in the japanese)?
2) Are you able to play original PS2 games from the US region?
Would this be possible? Could is possible get rid of the dvd/blueray zones (ie zone1 into zone2) by installing pal firmware? Or is the firmware on the dvd drive whats stopping the playing of the discs?
i thought of this too.. i was thinking would it be possible to download the latest ps3 firmware from the ps3 GB store slam it onto dvd. update from dvd. but i think all firmware released by sony are the same..
Does anyone know if putting pal firmware on a ntsc would work? Would it eliminate the ntsc zones and be able to play pal dvds?