I agree that at least for connectivity wireless solution could work very well. The problem is that not all the devices have a wireless feature and in many cases (you mentioned monitors and speakers. there are more...) with the current technology this is not feasible. And again if it was, then one should have to buy from the start all of his/her equipment. I am sure you prefer to stay with more cables, than buy from the start printers, scanners, etc. just for the wireless feature. You aren't Bill Gates to throw money ;)

A second point, that Andy mentioned, is that in many cases wireless means more wires :(

George