Basically whoever attempts this glitch in a real match will gimp the other player's team hardcore. Characters like Phoenix and Vergil are legit fucked... Phoenix especially.
The thing is that it's really hard to set it up in a real match. You need 2 meter, have them die correctly, you have to time it right etc. Unless it works on like other ways of hitting dead body characters. I think further testing is required to see if its doable off of other situations.
Also, your opponent has to not hold neutral, but keeping neutral makes him vulnerable. This could open up an interesting mind game. Will he keep neutral and hope you don't attack? If you think he's going to neutral, should you just smack him down and take down the anchor?
There are some details I'm not sure about. If you start hitting the first entering character in the air immediately, does that cancel the entry of the second? Can your opponent do anything to undo this 2 character state (ie. THC)? If so, can he do this immediately (since he technically does not have an assist to worry about)?
EDIT - actually if the one character is considered "dead", there's probably no way to get him back
EDIT 2 - forget the whole thing, either way you lose your character, might as well block and have two characters at once.