Google has announced on its Book Search blog that it is now offering results for magazines.
As a test drive, I used the search term "genealogy" and also limited the results to only magazines.
Using the "cover view" gave me an idea as to which magazines are currently included. It appears to be mostly popular magazines and not genealogy or family history magazines, which is to be expected.
But when searching for your family surnames this might be something of value to the genealogist/family historian.