A poster on another thread said it looked like the grand-jury was being bypassed in order to persecute, er, prosecute Mr. Zimmerman. It actually seems supported by this Huffington Post article, which says:
And unless Zimmerman pleads guilty, the affidavit by itself, summarizing the investigation by the special prosecutor, will force him to stand trial without a grand jury having heard any evidence and returned an indictment, but simply on a hearsay statement from two investigators who summarized their version of the evidence.
Things are very "interesting" if that is the case; as it is a clear violation of the Fifth Amendment.
I think the only Florida law that needs to change because of the Zimmerman case is that grand juries should be required in any felony charge.