The one Andrew has shown is a villa we stayed at a few years ago, I believe now under new ownership.
We always look for a sheltered and private pool area and have never had a problem, it may require a bit more time in your searching.
Sometimes the angle of the pool/home can be an asset, just because there is no fence does not necessarily mean the home is overlooked.
Many and I appreciate why prefer an open feel to the pool area, or some sort of lake or conservation view.
If you start by searching for a villa at the Indian Creek development (which is where Andrew's link is located) you will have a good chance because a good percentage of homes at IC are built with a privacy fence around the pool.
Two of the better websites are below, I have filtered the search so that you can just see Indian Creek.
http://www.villas2000.com/frbvo/Central/Indian_Creek.php
http://www.vr360homes.co.uk/Indian_Creek_Orlando_Villas.asp
We hope to book next month for an August 2010 holiday also, I will be amazed if I cannot found a secluded south facing pool, with all the other things we look for too, VCR & DVD etc
If you really get stuck I have at least 10 villas saved 'somewhere' and all are private at the back. Just let me know