Guess I will have to throw out some ideas...
1. I would love to see EFL integrated/supported in LinuxICE. To see an example of what that could end up looking like, see enna.geexbox.org. I know EFL libraries are like FOREVER in development, but at least the guys are starting to talk about an Alpha release.
2. Add playlist support
3. I'm not sure about this one: Make sure LinuxICE plays nice with pulseaudio (given that is the default setup, and no I don't know why, of most distros)
4. Use the database to its full extent.... ie: add in searching and basic library management capabilities
5. Since I haven't had a chance to try out your recent changes -- this may already be fixed, but add in the ability to continue from where you left off after a restart (maybe save position of the song / video every 30 seconds?)
I'm sure I will come up with more ideas as I think about it....