Opps, question posted May 2008.
Termites are a part of the environment. Nothing to get excited about.
Termites, just like water intrusion, if left unabated, WILL effect the value of the home.
If structural damage is caused, and the roof line resembles a saddle,. you can start deducting value in $10,000 increments.
Annual treatment, and keeping wood off the roof, eliminated water sources, is the best way to protect your house from a saddle roof. There is no shortage of 1920 constructed frame homes that are still standing proudly here in Florida where termites, sand, torrential rain all combine to make home owning an adventure.
Don't sweat it. Sign up for annual treatment then follow your real passions to celebrate life.