Ads have been run along side a very select few user channels on the YouTube site for a handful of months but these reports indicate that the program will be made much wider and be taken off of the site all around the web. Google has run very limited video advertising already but nothing like what it could do with YouTube's huge catalog. The ads will be persistent banners outside the frame and fading in-frame overlays.
It's a simple story, but if it is true it is going to blow the world of online video and advertising wide open.