My hookup isn't as sophisticated as Brian recommended, but does use some of the same hardware.
The bedroom system is a Vista Home laptop with all the Windows Media Center components.
The remote has all the capability of a top line PVR.
It's hooked over the LAN to a remote dual-OTA-tuner Silicon Dust box.
Mostly, it records all my favorite OTA shows in HD onto a 500gb drive.
Another server sports 4+ terabytes of movies, sports, and TV series, from various sources.
Both these systems (and others) share their hard drives to the house LAN.
A simple media player box in the living room plays these files, as well as access the intrernet for Netflix, YouTube, etc.
To add more playback stations, I would add more (inexpensive) Western Digital media players.
But then, my philosophy is different.
I focus on pre recording and downloading desirable shows.
Alternatively , having the remote for an HTPC in your hands, is more friendly to channel surfing, and is what most users expect.
I'm sure you & your wife will be very happy with your system.