Despite minority sports such as ski jumping now being broadcast in glorious HD, Bernie thinks that the time isn't right for one of the few sports that gets about 500million viewers that would look fantastic in high-def

From ESPN:
"Bernie Ecclestone has also warned audiences not to hold their breath for the introduction of high definition broadcasts of F1. Despite most other sports adopting the new technology, Ecclestone insists that there isn't enough demand from TV stations to make HD worthwhile."

In other words he's too tight to fork out for the equipment unless it makes an instant profit.

http://en.espnf1.com/f1/motorsport/story/8823.html