As with others - everything I have is connected to my receiver. It also is noteworthy that my receiver is 50 feet from my family room and the cable box and most other gear is in the basement. So, the single video runs to the plasma/projector are enough to deal with.
Turning on/off is all handled via a Crestron control system so it is a one touch operation to turn on the receiver, plasma, etc. No need to use the cheap speakers even if I wanted to.
My sub is set to auto though - it powers off after about 5 minutes of non-use.