Apple is stuck with pipeline crap. They are stuck at OpenGL 2.1. Still no upgrade with Mac OS X 1.7.
As for the file systems... Windows went from FAT to NTFS. Apple also upgraded but I don't know why. Linux is currently in need of a good SSD solution so hence the mess over there. Yet every filesystem in Linux has it's particular advantage.
Linux is more or less a pile of Lego. What you probably are after is the distributions. Well... There is no good tablet edition UI for Linux, I'll gibve you that. What would also help is more people being funded to work onthe graphics acceleration arena. It's comming though. The question is when the FLOSS drivers are at an allround polish level... r300 realy is too old...i wonder google and intel will build some new and clever os . something linux does not seem to be able to create : a working gui with drivers and easy to-go