I got ANOTHER request ;)
A VPN server for a future release.
PPTD or OpenVPN maybe?
I don't have much experience on VPN but I think it will be a great addition to your firmware.
You will be able to reach your NAS (and other devices in your network) from everywhere in a safe way.
If I'm right you will also be able to use public Wifi hotspots without being sniffed by someone (correct me if i'm wrong).
Very usefull for smartphones!