@, dejanbinladen, GunGod
I was intrigued by same question @i4memory, so I did some researching.
I found pictures of 5 different board revisions (1.00G, 1.00GT, 1.03GT, 1.04G, 1.04GT), but there could be up to 10, if you see the pattern.
1.04G is probably the final and most used. CPU-Z says rev. 2.xx for it, but I saw it says 1.xx on some pictures, probably on older revisions.