I'm not big on the idea of video game remakes either. Especially now that so many classic games are being made available on consoles through download. But they have their rightful place in the industry.
To me the real importance of remakes of reprints/downloads of old games is to make them more readily available to a new generation of gamers who may have missed out on them the first time. Video games are a form of art through and through, and preservation of their history is important. In the case of remakes it gives new players an incentive to experience something that's more contemporary, something they're more used to, kind of like how some people can't get into black-and-white movies. "Wind Waker" aged really well, and it's only been 10 years, but hey some people may just be like that and you can't always change their tastes.
Of course the other thing is refining the gameplay. My biggest problem with "Wind Waker" was the difficulty balance; it may have been an overall great and fun game but it was just way too easy.
And I will say this: if you just want to replay the game or introduce "Wind Waker" to a new player and don't care about the changes, I don't think it's worth the 60 bucks. And I say this because later on the Gamecube version will most likely become available as a Wii U download at a bargain price.