One thing that I liked about Tony Blauer's Cerebral Self-Defense tape was when he stated that to become proficient in deterring an attacker you must think like a mugger would think.
If I was a mugger what would I do if...
The person dropped his walllet.
Do not bend over to pick it up. Order him to back away and turn around.
Tried to attack me.
Stab or shoot immediately.
Ran for cover or around me.
Shoot or attack immediately.
You have got to realize that anybody who makes mugging a career is pretty good at it.
Probably as good at what he does as what you do for a living. He has seen almost anything that you can do to try to trick him.
I do not think that he would bend over to pick up the wallet. Would you? I would order you to turn around and start walking. Then when you are 4 or 5 steps away, I would pick up the wallet and run.
I would hand my wallet over to the mugger, and let him make the next move. If he does not show a gun or knife and tries to take the wallet out of my hand, I have many practiced options that I can use to attack him at that distance. If he has the gun or knife out I will give him the wallet. As Vladimir stated, you can always get a new wallet, credit cards and license. Is it worth risking your life if the mugger just takes the wallet and makes no attempt to hurt you. The alternative could be a coffin.
As Van put it "it must be pretty lonely in there."
Now if the mugger has the wallet and still makes an attempt at physical harm. Then everything that you have said in the last few posts make sense. I would do any type of combat and act as a viscious animal, (even talk to Elvis

) to keep from getting killed after I have given up my personal possesions. Who knows I might even get my wallet back after I had pummelled him into submission.
I still think that you should surrender your wallet if the attacker has a weapon and you have no readily available weapon other than Martial Arts. I would say anything (VSD) to make the mugger know that I am not going to be a threat to him, such as, "please take my wallet and go. I wont move until you are gone". If he goes away without hurting me and has my wallet, so what. I am still alive and will live to see my children get married and have children of their own. This is more important to me than credit cards, money or a license.