Actually, if you reread the Orlando Sentinel blog cited, it says, "They are restricted to a start no earlier than Aug. 20 this year." (My emphasis.) That is because this year (2007), August 20 was 14 days before Labor Day. Later in the entry, it references, "the law requiring schools not to open earlier than two weeks before Labor Day." Again, my emphasis.
That is the current restriction under statute, schools may not open any earlier than 14 days before Labor Day. In 2008, that date will be Monday, August 18. Barring legislation changes, all indications are that Sarasota County will approve a calendar with an 8/18 start date. As I said in my pp, I would expect most FL counties to do the same.
t-beri is correct that some are trying to undo the "Save Our Summers" legislation. I, for one, wrote every FL legislator last year suggesting facets of the public school system that needed their attention much more urgently than the calendar. What really helped that legislation pass was the backing of the tourism industry, claiming that having Floridian students return to school so much earlier than their northern counterparts deprived hospitality businesses of inexpensive teenage labor for the last month of the summer season. It's always about the money--sigh.
Sorry about the editorial comments, stepping off soapbox.