There was a new version of the official PS3 firmware released by Sony over the weekend, called version 3.56.

This release is needed to access the PS Store and to log into the PSN network for online play. Anyone still using 3.55 will not be able to go online or access to the PSN network at all.

It is said that Sony were working on this ever since it was known that hackers had broken the FW and released a CFW that worked. Sony also took the measure of placing a restraining order on the person presonsible for cracking the PS3 firmware's security codes, so the updated version wouldn't also be hacked in the same way. Sadly for Sony this didn't help at all because within the first hour after release it was announced that it had been cracked (some reports within 10 minutes), and by a completely different known hacker in the scene.

Hiowever, whilst it has been cracked, there isn't yet a new 3.56 version CFW, so if you want to continue running homebrew and backups you will need to stay using a 3.55 CFW, and lose the ability to access to PS store or go online. If you do update to the official 3.56 release as it will stop you playing backups and homebrew and you can't downgrade back to 3.55 (at the moment).

I'm sure a 3.56 CFW will be here very soon.