If you're into desktop functionality, better VNC implementations are badly needed. It's not intuitive on most desktop distros how to configure a remote desktop solution correctly. We're nowhere near the "it just works" quality that RDP has on Windows.
If you're into hardware, I suspect there's work that needs to be done with BD-R DL/XL support. I don't think I've ever successfully burned a multi-layer Blu Ray disc across multiple distros, burners, and drives.