Know this is really far out... Dual WAN support, Support for VPN, perhaps support for a 3G/4G cellular fob or hotspot as a backup connection..
Unfortunately the fob id want to use is going to be discontinued at the end of Sept (Infomark 910 Wimax hotspot, but you can use a mini usb to USB cable to connect it to some devices,,, i.e. asus routers and PCs and its can be used through the USB vs the wireless)...
Not sure how much RAM and CPU are available but later ideas are things like CUPS running a linux google cloud print/airprint server.. Stuff to make mDNS/Avahi/Zeroconf/Bonjour play nicely through the router, possibly even recognizing the router and connected devices.. proxy server functions for filtering content (Already have a adtrap to do this though), Perhaps a Media Server? Im just throwing out ideas...
That said, the most requested feature is for the almond+ to fail gracefully .. when iv misentered a wireless pw and tried to use wireless repeating.. iv had it lock up.. or 5g decides to vanish.... or it becomes stupid untill i reset the router completely with the button.. rebooting usually doesnt fix it.. it will freeze after a button push.. but its fine once i reconnect properly (if i can see the device)...