It's an HD remaster. The lighting is far superior and it's all in HD, so it's crisper/brighter/more colofrul. The actual graphics themselves aren't going to be upgraded, it's just thrown into HD and then they are adding gamepad support/controls, think how they did with MGS HD collection, same game just upgraded to HD. I'd much rather this WW HD remaster than nothing at all until the next big Zelda, if they chose to do WW over other ones than it's cool with me, as I wasn't expecting any at all.
I'm just glad that I'm going to get to play an HD remaster of a great game that I haven't played in many years and don't have the console to play even if I wanted to anymore.
I actually have never played it because right after majoras mask i was expecting something quite different so I guess i'll play it this time around, I hope they make a new metroid game soon they haven't made one in a while and it was the worst one of the series unfortunately