Wuhu Island will be totally worth revisiting.
When I last saw PilotWings Resort, I was impressed by the 3D effect, the controls, and the presentation. None of that has changed. It still has a nice 3D effect, good controls, and a pleasant Mii-focused art style. In this set of impressions, I'm going to run down what I played in the new demo at Nintendo's 3DS event in New York City.
In general, the game is set up into two modes: Mission and Free Flight. The latter is self explanatory, and is very reminscent of one of the Air Sports modes in Wii Sports Resort, as you gently travel around the island hunting for new items of interest. The Mission mode is where the meat of the game is, as it gives you a number of different focused tasks to perform.

In the plane section, they showed off two mission types. One had you flying through rings, while the other had you shooting targets. The plane can do a barrel roll, and you can even fly with it upside down by holding the L and R buttons down. While the two missions types weren't very different, they were both fun.
The rocket belt (jet pack) was also present, showing off platform jumping as you had to manage the contraption's fuel while trying to land on spaced-out target-like platforms.

Lastly, the hang glider was playable. The hang glider doesn't have any acceleration of its own, so you have to use thermals (sections of hot air) to gain altitude. You can also take pictures when you're using the hang glider, which is required in some missions. Those pictures can also be sent to the 3D Camera, where you can put them on your SD card and on to your computer.
PilotWings Resort is a launch window game, meaning it will come out between March and June.