I wouldn't recommend doing what the OP is talking about here. Adding that much overhead to 3 wireless connections in the name of saving ~300mb of hard drive space on the other machines is just a bad idea full stop.
Hey apop.
I think I disagree with you here on this one. I'm also in the same situation starting to create a home server environment, and am also currently setup to share a central database (also using the moving pictures and my tvshows plugins).
Its all working nicely, but is currently slow on my wireless G network. It takes me a good 10 seconds to load things on my laptops from the home server.
But......the point of the home server is specifically not to have to have the duplicate and triplicate the files onto multiple machines. I'll be upgrading to wireless N soon to hopefully fix some of the slow issues.
By keeping every thing on the server, the goal is to have a "Thin" front-end machine, making them as quiet as possible. And quiet to me means no moving parts.