From the press release:

Marvel is pleased to present your first look at two new Amazing Spider-Man variants from superstar artists Bryan Hitch (Amazing Spider-Man #645) and Paolo Rivera (Amazing Spider-Man #646)! Origin Of The Species, from the pulse-pounding creative team of Mark Waid and Paul Azaceta, continues as an army of Spidey’s greatest villains sets the stage for one of the toughest fights of Spidey’s life. The odds are stacked against Spider-Man as he and Harry Osborn fight side-by-side in a battle to save Harry’s child.  The people Peter Parker cares about most are in danger, and someone won’t live to tell the tale! Be sure to catch the last two chapters of the greatest Spider-man Epic comes to a close this October in Amazing Spider-Man #645 and Amazing Spider-Man #646 !

AMAZING SPIDER-MAN #645 (AUG100553)
AMAZING SPIDER-MAN #645 HITCH VARIANT (AUG100554)
Written by MARK WAID
Penciled by PAUL AZACETA
Cover by MARKO DJURDEVIC
Spidey Vs. Variant by BRYAN HITCH
Rated A …$2.99
FOC – 9/23/10, On Sale – 10/13/10

AMAZING SPIDER-MAN #646 (AUG100555)
AMAZING SPIDER-MAN #646 VAMPIRE VARIANT (AUG100556)
AMAZING SPIDER-MAN #646 RIVERA VARIANT (AUG100557)
Written by MARK WAID
Art by PAUL AZACETA
Cover by MARKO DJURDEVIC
Vampire Variant by MIKE MAYHEW
Spidey Vs. Variant by PAOLO RIVERA
Rated A …$2.99
FOC – 9/30/10, On Sale 10/20/10

Related posts:

1. Your First Look at Bachalo’s Amazing Spider-Man #644 Variant!
2. Your First Look at Amazing Spider-Man: Origin of the Species!
3. Marvel Unveils Joe Quesada’s Variant to Amazing Spider-Man #640
4. Marvel Unveils Joe Quesada’s Amazing Spider-Man #638 Cover
5. A Six-Page Preview of The Amazing Spider-Man #612