Florida will be an Arizona/Missouri-esque lean R state in 2016, officially. It already is there now; just nobody believes it.
Florida is "Lean R". It split on Bill Clinton between 1992 and 1996 when Bill Clinton won 100 more electoral votes than he needed. It did decide 2000 and went clearly for Dubya in 2004. It was more R than the US as a whole in 2008 even if Barack Obama won it; it was much more R than the states closest to the national average (New Hampshire, Iowa, Colorado, and Virginia).
President Obama does not win Florida state in a 50-50 election. 51-49? Maybe. He could win Ohio or perhaps Virginia in a 50-50 election, but definitely not Florida (or Arizona, Indiana, Missouri, or North Carolina). If he wins Florida by 5% he is probably picking up the sorts of voters who went for Clinton in 1992 and 1996 that the Democrats have never won since 1996 and is likely picking off either 450 or so electoral votes with about 56% of the popular vote. But that's not an interesting election, at least for the Presidency.