Viacom's billion dollar suit will lead to self-censorship at the very least.
Personally I don't see how the quality available via YouTube would cut into any of the business of Viacom. The sound is tinny and the video pretty low quality. If I was Viacom I'd build my own free video model and include advertising instead of suing. But what do I know? I'm just a consumer that finds YouTube pretty damn cool.