I think it would be really cool if there were a Linux distro out there, possibly based on an older kernel, X server, etc. designed to work with deprecated software and hardware, while still patching some of the security exploits fixed in later kernels and such.
For a while I had a laptop that was too slow for Windows 7, but also had graphics hardware too old for acceleration under Linux, and since Windows XP had just ended support at the time, I was kind of stuck in a weird spot. 😜 That laptop has long since been trashed, which is a shame as it served me well for a little while, but I still have an even older laptop in storage that had similar problems. It's in decent-ish shape too, so I'm thinking if I ever get it up and working again that I'll dual-boot a lightweight Linux distro on it as well as 98SE(!) just for running games. It ran XP originally, but it's still a bit heavy for my liking, and it's too much of a target for security vulnerabilities, so for stuff that requires Windows I may as well run a version that doesn't even support the onboard wifi.
Along with getting really crappy old laptops up and working, I could also imagine something would be nice for running things like the original boxed Linux versions of Unreal Tournament and whatnot.