Whilst writing this how-to I also tested Ubuntu's distribution with my PS3 because it seems a better starting OS for people getting into Linux for the first time. Everything is nice and shiny and there are so many tutorials written for Ubuntu which quickly teach you how to do everything. Unfortunately due to the PS3 2.0 firmware update, the networking was broken and I was unable to find a work-around. We just have to hope Sony hears our cries and fixes this in the next firmware update.
YDL is adequate as an OS, but I dare say it has not got the support base that other distros like Ubuntu, Red-hat and OpenSUSE have; and because of this it can make it hard to find out how to do things in YDL. Also, while their new GUI (called Enlightenment or "E17") is very shiny, it detracts from what it is actually supposed to do, be a desktop. You don't get the feeling you really have a desktop machine, but more of a media center which defeats the point of installing Linux. The XMB operating system is already ideal for playing games and dishing up media in that respect.
Linux performs amicably on the PS3; it really shows that the cell architecture of the system can be put to use in an everyday situation.
That in mind, it isn't fast. The hardware it is run on is limited with less than 512mb RAM and each processor only being 400 MHz, so just because you have eight of them doesn't mean everything will run as though you have 3.2 GHz on tap.
When Sony helps fix the network problem (or the YDL team patch it), having Linux as a second system could prove quite useful.
Easy to install
Provides a desktop type machine in your living room
Supports more media formats than XMB (through Fluendo)
Slower than average performance
Lack of "free" codec availability