Blue light just stays on & the loading icon/clock just keeps spinning.
I presume it's not possible to roll back or download the previous firmware from somewhere?
Can you get into safe mode? Not that it would do much good as you won't be able to install a lower version firmware but you can try installing the current update again.
Accessing the PS3 Recovery Menu (Safe Mode)
With the system in standby mode. Press and hold the power button down until the system turns on and then off again. Release the power button. Very important to hold the power button until the console shuts off and to release the power button before continuing to step 2.
After about 1 - 2 seconds press and hold the power button again, until you hear 2 consecutive beeps. Release the power button. During this step you will actually here three beeps. There will be one single beep then a short delay followed by the 2 consecutive beeps. Only release the the power button after the 2 consecutive beeps.
You will then be instructed to plug in a controller, via the usb cord, and press the PS button.
At this point the PS3 Recovery Menu will be shown on the screen.