We have noticed that most Apple Macs we are now leasing are being ordered with Windows as an OS as well. We can offer this in two ways either under Apple Boot camp which has the advantage of being fast but the disadvantage that you cannot switch OS without a re-boot.
We also offer VM Ware or Parrallels which allows Windows to run within a windows within the Snow leoard OS. Very convenient but can suffer speed issues as technically the Mac is running two operating systems. This option can be specified on our websiteb at time of ordering. Delivery is only delayed by a day over our normal 2-3 days delivery time.
Both these options we will pre-install before shipping to ensure all drivers etc are installed.