Softness in Social Networking Advertising?

The Deal reports here that Viacom is very bearish on the prospects for advertising on social networking sites. That may or may not be true but it would be interesting to hear advertiser feedback on advertising performance. (I have some opinion based on some limited campaigns thus far) Clearly Viacom is going a different direction with Xfire but given the amount of media that Viacom buys this could be the start of a bad trend.