Apple use AdWord advertising to show their Apple Add for the following key words.
Windows 7 download
Windows 7 upgrade
Apple is quite famous in this kind of marketing campaigns in history. This time Microsoft has clearly showed that they have answered the Windows Vista Complains through Windows7. Fixing all the compatibility issues and User interface problems.
On the other hand according to AdWord Terms and Conditions it is not appropriate to use some other brand name to advertise your product. Let Google Microsoft and Apple can handle that later.
However for me it is faults advertising. Apple is damaging it reputation by these type of marketing campaigns. Apple is branded and has different market where Windows target a different set of audience.
One thing is proven that launch of Windows 7 is already become a threat to Apple.