Yesterday Sony announced on the Official Playstation Blog that in the newest PS3 firmware update (v.3.21) which releases April 1, Sony will remove the ability to install an alternate operating system for "security reasons."
If you are currently using this feature on your PS3, you can choose not to download the update, however you will also lose access to everything on PSN, you won't be able to playback Blu-Ray discs which require firmware 3.21 or greater, or use any new features available in the future. So you're pretty much boned.
We haven't heard much about this feature causing any problems with Piracy or other security issues on the PS3, but Sony must be concerned about something right? Why else would they put out an update that REMOVES a feature. Maybe it's an April fools joke?