It may not have been popular, or even easy, but the simple fact that a PS3 could boot and run Linux was a pretty awesome bragging right, one that will be phased out on April 1st. According to the official Playstation blog April fools day will mark the release of Firmware version 3.21, and the death of the "install other OS" option on non slim PS3's.
Sony wasn't really specific as to why support for such a long-standing feature was being dropped, but like everything that's hard to explain "Security concerns" was picked as a blanket excuse. If you followed our How To guide last year to get this up and running, now might be a good time to say goodbye to your Linux install if you plan to keep using your console for online play.
April fools day is a terrible occasion to try and convince people you're making a serious announcement, but the fact that they are giving us almost a weeks notice makes me think they are serious about this one.