On first glance I would say not enough RJ45 sockets. In my lounge I have 6. One for Wifi Access point, one for XBMC, one for the video from DVB-T (housed in the garage) box and one for the stereo sound from the DVB-T box. Did have another one used for the cable box but no longer use this. So I have 2 spare. Also for the master bedroom I would have at least 2 more sockets.
One question have you allowed for future expansion. This can be done by running more conduit so you can easily add cable in the future.
For whole house audio you can't beat the Sonos system. Mind you the Logitech Squeeze box is starting to become a serious contender now.
Something you might consider is the use of leaky cable for the wifi. This requires one access point with 2 aerials (one for incoming signals and one for outgoing signals), you replace these aerials with the leaky cable. It can solve the problem of wifi blind spots. This could be installed behind the skirting board.