NOTE: There is now a comprehensive installation example here.
Before being able to use it, you will have to compile wmi-client for Linux.
2. Install stuff on the Linux box to support compiling (package names may vary depending on you Linux distribution)
apt-get install autoconf python libdatetime-perl make gcc
3. Download stuff
This is actually from the Zenoss project, to whom most of the credit should go:
4. Bunzip and untar stuff
tar -xvf wmi-1.3.8.tar
6. Find something else to do for at least 10 minutes, compiling takes time
7. Test it
wmic -U DOMAIN/USER%PASSWORD //HOST "Select * from Win32_ComputerSystem"
You should get lots of information from your target Windows machine. Be careful, wmic requires a forward slash and NOT a backslash between the domain and username.