I really don't know why so many people think NV is a Tossup in a Democratic wave. It's not as if Heller is a particularly strong candidate either.
Major Prognosticators feel it's best to give the benefit of the doubt to the incumbent when the election is many months away, due to the fact that, historically speaking, the incumbent reelection rate is very high.
This, plus I'm not sure I've seen any polls with Heller firmly down by even a couple points.
I still think it's a bit premature to put Florida is a toss-up though
It's supposed to measure the state of the race atm, not in a year.
