Even if what cmt says has truth it does not mean that Mr.Zimmerman did not murder or was not capable of murder. Here is an article with cmt's uncredited answer it speaks of Mr. Zimmerman in a low and high tone but the reality of what happened is not found in the depicting words of the article.
Mr. Zimmerman like every other breathing person has a good side but as every person knows we all also have a bad side. (in part/ my censoring)
....."The 28-year-old insurance-fraud investigator comes from a deeply Catholic background and was taught in his early years to do right by those less fortunate. He was raised in a racially integrated household and himself has black roots through an Afro-Peruvian great-grandfather - the father of the maternal grandmother who helped raise him.".....
To me it is the end of the above article that speaks the loudest.
....."Ten days after his father was hospitalized, Zimmerman noticed another young man in the neighborhood, acting in a way he found familiar, so he made another call to police.
"We've had some break-ins in my neighborhood, and there's a real suspicious guy," Zimmerman said, as Trayvon Martin returned home from the store.
The last time Zimmerman had called police, to report Burgess, he followed protocol and waited for police to arrive. They were too late, and Burgess got away.
This time, Zimmerman was not so patient, and he disregarded police advice against pursuing Martin.
"These as*holes," he muttered in an aside, "they always get away."
After the phone call ended, several minutes passed when the movements of Zimmerman and Martin remain a mystery.
Moments later, Martin lay dead with a bullet in his chest."
http://www.reuters.com/article/2012/04/25/us-usa-florida-shooting-zimmerman-idUSBRE83O18H20120425
In terms of how or if there will be "a change" I do not know of anything that happens and does not create some change. Question here is will the change be to one single insignificant person or will it be a sweeping roar throughout mankind? My bet is that it changes many persons thoughts on how a murder can be justified.
Now Mr. Zimmerman will get his Kel-Tec 9mm handgun back and he will feel more protected in shooting the next person because, Mr. Zimmerman was in fear or his life from this (dead) person unhappy with the not guilty verdict. Just like Joe Horn, Mr. Zimmerman will quietly drop out of the public's sight and mind but will he be able to stand the mental tortures of shooting a man?