I know I'm late to this Q and thread, but for the upcoming classics and other road events the place I go first for cycling video feeds is
he started a few years back and for my dough has the most comprehensive reach for pro (and high level amateur) road cycling stuff around. Great guy, still puts up a bunch of local video and is true tifosi to the soul!
cyclingfans.com, as carbonissimo notes, also good
also has good feeds, bu these are about as real time as the web gets, so when its over, its over...
biggest issue is 'english', most often you have to become 'fluent' in some other language quickly. Knowing the rider names helps, cause when you hear a bunch of jibberish and then a 'name', at least you can sus out a little of what the announcer might be spoutin... but english sometimes does happen.