I just thought that I would finally post a little something about WQL (WMI Query Language) queries for Group Policies. It is regularly observed by most of my customers that examples of WMI queries for GPOs are found here: http://technet.microsoft.com/en-us/library/cc758471(v=ws.10).aspx#CommunityContent .
It is important to note that these are examples and are not optimized by any means, they are there to provide the various options to filter policies from machines/users that match certain criteria. If you are looking to implement a WMI query, the first thing I would suggest is to ask yourself this "Can we use preferences and item level targeting instead?" If the answer is no, then implementing WMI filters are not an issue, as long as you stick to these simple guidelines:
Just a few thoughts and ramblings to get you started :)