Apart from being very jealous, I would think very seriously about putting fiber into each room. In my experience, the best and most reliable DVI/HDMI extenders are the fiber ones. Even if you don't need it straightaway, if you intend to live there for a long time it could save you a lot of hassle later on.

Last time I checked the price of CAT5 has rocketed in the last few years, to the point where it wasn't that much cheaper than CAT6.

Make sure that 'everything' goes in the apps room/basement. Nothing looks slicker in the living room than 'just' a Plasma/LCD or projection screen and nothing else.