I own L4D but I've got a certain history with the RE series. My friends and I have (over the years) played through the games and normally swap in and out while playing. To have my friend next to me gunning down those same zombies.... bliss.
As for the walk and shoot, it just makes me wish even more that 1) developers took the Wii more seriously (RE4 on wii rocks and a good shooter off that system is soooo fun) and 2) The Wii had the capability to port over directly (this would give developers less of an excuse)