I change my own belts too, and have never seen one looking that bad. The last ones I changed (after two years and 5000 miles) looked almost as good as new - albeit they'd slackened a little.
Here's what one of the most respected Ducati 'gurus' says about potential problems:
http://www.ducati-john.co.uk/ducati-points.htm [Edited on 22-2-2006 by weeveetwin]