If possible, I would recommend getting a wired solution between at least your broadband, your computer and your home entertainment system. That is going to give you a lot of reliability and a minimum 100 megabit connection speed between your media location and your computer.
Having said that, at the moment, I don't have a wired solution myself. I will move that direction as soon as possible though. I think that it opens up a lot of possibilities that being exclusively wireless leaves out.
Here is my configuration at the moment:
Cable Internet->Linksys WRT54G (running DD-WRT firmware)
Hard wired->iMac G3 (for kids), Linksys PAP2 VOIP converter
Wireless->iMac G5 (main computer), Apple TV (which I do NOT stream video to), Airport Express (for AirTunes), iPhone
I'd like to run wires to my iMac G5 and Apple TV. I would also like to hook up some sort of networked storage, although for my current configuration, an external Firewire/USB array for backup would probably be sufficient. The wired network would give me a much faster, more reliable connection between various locations. Wireless would still be available as an option for AirTunes, laptops and iPhone, etc.
I would be very interested in some sort of iTunes media server option that would be a central storage place for all my audio and video files. That way, I would have access without having to have my computer running with iTunes up (which I actually don't do now). However, no such device exists right now. With all the various hard drives/storage I have (computer, Apple TV, two iPods, Apple TV, etc.) it would be nice to have everything centralized and shared - but not on the computer itself.