They've been saying that since at least Katrina... I've yet to see definitive proof of it being true mostly because you can go back in time and see on and off cycles of really powerful storms.

Edit: Here is the closest I've gotten to saying yup that's it.

Well, it's a question of your horizons. If you're worried about global hurricane activity--remember that only about one in 10 storms occurs in the Atlantic; the rest occur elsewhere--and if you consider hurricanes over their entire life and not just when they make landfall, you really do see an upward trend in the power of hurricanes, not in their frequency but in the magnitude of the wind speed and also in their duration. But you really can't see such tendencies in landfalling storms in the US simply because the numbers are so small. You're just--it's impossible statistically to detect any kind of meaningful trend in that.

I do only tend to see the ones that where I am.