There are several interesting new filesystems in development. HAMMER is really specific to DragonFlyBSD, but btrfs and Tux3 are both being developed for linux specifically, and all three are attempting to leapfrog zfs. All will make storage a simple question of capacity, and largely remove the concerns of configuration and data integrity. These will be strong advantages over any commercial OS.

There's some substantial activity on the biggest closed source black spots in the linux kernel, drivers for NVidia and ATI graphics cards. The open source versions lag quite a bit behind their propritary counterparts, but that gap will probably narrow.