I've noticed that for some runnings of major Euro races, such as the Arc, the British media have used a racecaller and a commentator during the broadcast of the race. The caller goes through the field for the first half mile or so, the commentator chimes in for a furlong or two, then the caller takes over again.
http://www.youtube.com/watch?v=ctctz...eature=related
Something like that may be appealing to a TV audience. The replacement for Durkin can take the field through the first turn. Byk can provide some perspective as the field runs down the backstretch about the pace and where particular horses are placed. The announcer can take over again as the field hits the far turn.