If the investigation is complete, and Police are issuing statements that witnesses, which support guilt, are inconsistent, it doesn't look like formal charges may be pending. At least that's how I read it.
That's how I read the tea leaves. A new investigation, an independent one, is also being undertaken. Some conclusion ought to come within the next couple weeks - should be sooner, but the authorities may be waiting to see if tension just ebbs of its own weight, first.
Here's something for the Nancy Grace's and others who took Crump's bait that "the video shows no injuries."
Race, Tragedy and Outrage Collide After a Shot in Florida - NYT - April 1, 2012 (on page 6 of the long article)
Mr. Zimmerman, meanwhile, was taken to Sanford police headquarters, where, he told his father, the police took many photographs of his injuries. His father said that he had a broken nose, a swollen and cut lower lip, and two cuts on the back of his head.
The article is quite biased (against Zimmerman) in its presentation, but has plenty to allow a "absence of probable cause it was NOT self defense" conclusion by the press, at some future date. And they'll claim that was the position they'd held all along.