Most of the stories about this list have pointed out that it doesn't necessarily contain passwords from Gmail, but from various accounts that used a Gmail address as a username.

Someone on Slashdot searched for "+" suffixes in the list, as in [email protected]:

http://tech.slashdot.org/comments.pl?sid=5680529&cid=4787421...

Some of the most popular suffixes were xtube, daz (and daz3d), filedropper, and eharmony. The two characters returned by isleaked.com for my address could indeed have been from daz3d.com.