Businesses and individuals are being encouraged by antivirus and internet security companies to use an unofficial patch, available here [scroll down to green box], created by Ilfak Guilfanov an individual.
Microsoft has recognised the problem, but will only have an official patch ready by January 10, 2006
The patch has been checked by the security companies to ensure it is legitimate and safe and there is a good article about the WMF File exploit and patch on about.com with more info.
Perhaps the real question, however, should be… ‘Why will it take Microsoft almost 2 weeks to fix the problem, with all their resources, when 1 person can create a temporary fix in just a few days?’