An adviser to the European Court of Justice just issued an opinion that "Google has not committed a trademark infringement by allowing advertisers to select [trademarked] keywords".
While the opinion is non-binding, the court is generally expected to follow the opinion.
Google has moved to aggressively open up trademark bidding in the US, the UK and a number of other nations, however advertisers in most European nations still operate under an older search trademark policy. Under the current policy, trademark owners can register their trademarks with Google and Google will prevent any advertiser from purchasing those terms.
If this court case is found in favor of Google, I would expect Google to begin to liberalize its policy in the remaining European nations that still have some trademark protection in paid search.