#1: Draws its inspiration from Savage Tales #1, a Marvel B&W anthology from 1971. Ka-Zar appears in both.
#2: A movie poster homage. Jaws in this case.
#3: Dawn of the Dead of course! The best of the Romero zombie flicks IMHO!
#4: The world is Deadpool's it seems with this Scarface homage.
#5: Yup. Pretty Woman.
#6: An homage to one of the best movie posters in history, Ridley Scott's Alien.
#7: Another movie poster homage, a little more obscure this time. Inspired by the promo poster from Trainspotting.
#8: One Million Years DP, inspired by One Million Years BC. Easy enough.
#9: An iconic image from The Graduate.
#10: Why Frank Miller's Wolverine #1 cover bub!
#11: From the superlative Lone Wolf & Cub, published in the states by Dark Horse.
#12: The only album cover in the mix, Nirvana's breakthrough album Nevermind.
#13: The final issue is an homage to the Silence of the Lambs movie poster.
There's a lot of Deadpool cover homages out there and what looks original may in fact be a reference to a movie, an album cover, or some other notable piece of comic art. For example Deadpool Corps #6, new on the stands this week with a cover by Rob Liefeld seems awfully familiar...