Mostly great product so far. I'm impressed with what's there already and can't wait to see what some of the later firmwares bring. That said, here are a couple of things I'd like to see implemented over time.
1) WOL
2) Access restrictions - ability to block clients or mac addresses to certain times of day, certain sites, etc.
3) VLANs - both for individual ports and to force guest wifi to Internet only
4) Ability to change username from root to something else
5) Radius implementation
6) GUI ability to hide wireless networks (I realize this can be done via ssh and/or router commands)
7) Ability to use ZoneEdit for DDNS