I found this somewhere:  Wolverine can die by decapitation as stated in the Xavier Protocals. Especially since Wolverine’s healing factor is no longer what it used to be: "Wolverine’s own healing factor found its limit, death, soon after this. Thanks to a revealing battle against the angel of death, Wolverine can no longer let himself get to the point of death, or he’ll die for good. "   

Writers have ignored that Angel of Death of crap for a years. He's healed from death many a time since then.

As healy as he needs to be because writers are never consistent

"As healy as he needs to be because writers are never consistent"

This.

@CaptainDoeo: Believe me, wolverine is healing and dying all over the place. Uncanny annual 10 he reconstructed (with help from a crystal) from a single drop of blood while his original body had its heart torn out. Don't read too much into it or try to be very scientific regarding his ability.

as far as decapitation its kinda hard when ur skeleton is made of adamantium

@XsPectre28: Well, there's space between your vertebrae, so he should be vulnerable to a decap, but I think they did some insane crap where they adimantiumed all his connective tissue ("then how does he bend?" you ask. Beats the hell out of me).

@roboadmiral: His healing factor messed with the adamantium bonding making it bond on a molecular level to his skeletal system so it doesn't hinder any movement and makes his joints super tough to rip apart considering Hulk couldn't it among other super strong people.

Nope.He has healed and saved himself from death many times.Just sometimes they make his healing factor kicking in a little bit late.