This issue is a variant of Justice League of America (DC, 2006 series) #1 [Cover A]. There exist further variants.
There are 7 variant covers for this book:
1-2: Covers A and B form one picture.
3: The Michael Turner cover was an incentive cover.
4: A variant available at the 2006 Balitmore Comic Com has both the A and B covers printed together sideways to form a single cover.
5: Another combined cover of A and B was used for the 2nd printing.
6: A 3rd printing of this book used Michael Turner's pencils as a cover.
7: A fourth printing used the Michael Turner cover again with shades of red, white, black and gray for the colors.
On page 6, panels 2-6 are taken directly from Justice League of America #106 (DC, 1960). Mariah Benes is credited "with special thanks."