The web is a buzz with news of the Google Adwords Quality score update. So far none of my clients have been affected so I can’t personally say what everyone is all torn up about but there is a 6 page (and growing) thread on WebmasterWorld regarding the change.
People have been complaining of keyword prices jumping up to 20x their original cost and quality scores going from ‘Great’ to ‘Poor’ at the same time.

Loren at SEJ has more coverage

According to Google, only a small number of AdWords advertisers will notice an increase in their minimum bids and the majority of advertisers will not be effected.

Publishers however are sounding off in forums (and these publishers probably have much more aggressive AdWords campaigns than the majority of AdWords advertisers)

Unfortunately, the Google Adwords blog has yet to mention any news of the update but I’ll keep an eye on it if anything changes or they decide to speak up.