Wii Sports Resort will have a new feature. It's called the "Wii-Motion Plus", and it makes the Wii-mote do more than ever. Before, you could point, shake, and turn the remote. But with Motion Plus, the Wii-mote is more accurate. This means you can throw a frisbee, sword fight, even ride a jet ski without defying the laws of physics! =D
Wii Sports Resort will be the first game featured to use WiiMotion Plus. Older games do not support the WMP, so you'd basically have an extra attachment for no reason if you played Metroid 3 or LoZ: Twilight Princess.
I hope you look forward to the Beach themed sports games as much as I do!