the issue here isnt the operating system. the operating system and it's API's can always be emulated, with programs such as wine. the issue here is that the PS2 uses a different processor architecture than most computers. SAH offers support for many architectures, including the MIPS architecture, though they only offer a client for MIPS with IRIX running on it. So if you can get your PS2 running with linux, then you compile a unix emulator, you should be good to go. It would be really cool if someone would offer a livecd that jsut does SAH and runs on the PS2.
edit: are you sure sony is developing it? im kinda doubting that. gentoo has a PS2 project going on. And there used to be a debian port for PS2, but the developer stopped work on it. the gentoo port is having some trouble as well. but what im really interested in is SAH on a gamecube. PPC to the end!!