The official statement made by Google Blog outlined the details, "We are proposing a settlement with the plaintiffs in this case. The proposal would allow advertisers to apply for credits for clicks they believe were not valid. Specific details of the settlement will remain confidential until it is presented to the judge. We do not know how many advertisers will apply and receive credits, but the total amount, including the legal fees determined by the judge, will not exceed $90 million."
There are other search engines that come under the scrutiny as they carry Google's ads. However, no other official declaration came from other search engines. Google's big network includes Ask, AOL and LookSmart. Mive and Yahoo! are on the safe side as both these search engines giants never carried Google's ads.
Nice way to prove that with Google, even if you loser in the short term, eventually you gain.