I personally think giving Link parents would be a little unnecessary. It has already been mentioned that Link is going to be the oldest to date, and like others have pointed out, he has no real need of parents. The mystery behind Link's parents has always been part of Zelda, and I don't think that's a mystery that should be broken. It was alright in Ocarina of Time when it's mentioned that his mother died during the war because her presence never interfered with the game and gave reason to Link's living in the Kokiri Forest. Likewise, it was explained in the A Link to the Past backstory, Sound & Drama, that Link's parents (Banzetta and Loretta) were slain, and there's the whole explanation of how he came to live with his "uncle". The info on his parents didn't interfere.
So why give him parents now? I don't think there'd be much of an issue if there was a small hint about his parents as long as they don't actually appear in-game. Even if he did have parents in SS, he'd probably be too old to even live with them anymore, making them unnecessary additions to the story. He doesn't go out and save the world to make Mommy proud, you know?
In The Wind Waker, he had Aryll and Grandma, but they were necessary additions to the plot. Without them, there'd never have been a reason to don the Hero's garb, nor would he have ever been caught up in Hyrule's ancient dispute with Ganon. He'd have had another normal birthday and gone along his merry way. Additionally, in The Wind Waker, he is a child. He couldn't have been on his own. Even Ocarina of Time Link had a parental figure- The Great Deku Tree. So, for the younger Links, it makes sense that there'd be a family, even if only a small one.
But Adult Link? No, he's a big boy. A parental figure is not necessary to a game with an adult hero. However, I wouldn't mind seeing them pull off something similar to what they did in Twilight Princess. In that particular game, Link, while without family, was very close to Uli, Rusl, and Colin. Rusl could be considered Link's father-figure; a mentor who Link trained under, worked with, and looked up to. That type of "parental" figure gives off a feeling of having a family bond without actually interfering with the lone-hero archetype. That is something I wouldn't mind reappearing.