The PS3 isn't selling because it costs too much to buy one. Lol (I own one, though.)
The one thing I do know about Zelda, is that a few of the games are all about style.
TLoZ on the NES was a very basic game. It had a short, plump little guy named Link running around poking other funny looking things. Just a fun game, not much to say in the style department.
Now, the jump to the next Zelda was definitely a change to style. Instead of a quirky little game like TLoZ, Nintendo went on a much darker path with AoL. The enemies were much more monsterous and menacing looking, the color pallet was much darker and not very vibrant, and the game definitely had its dark sides. With the introduction of people, came the introduction of back stories. The back story of why Zelda was asleep was pretty sinister, and there is even a whole town that had to uproot and move because the other became infested with monsters and is now a ghost town... populated by ghost monsters.
For the SNES, Zelda went right back to their first formula. ALttP was another quirky game, and though it did have some dark story elements, it was still appealing to the eye. It had one of the widest range of colors in any SNES game to date, and the art style was definitely fit for the game.
OoT went back to the "dark" side of Zelda, while MM, on the other hand, used a "dark" style of storytelling but kept colorful and quirky visuals.
The Gamecube games went in POLAR opposite directions when it came to style.
WW had bright, cartoony art style with a fun story to tell.
TP had a dark, gritty art style with a very sinister story.
Now, both of those games did have moments that went to the opposite end of their respective side of the spectrum, but it's obvious that one game (WW) generally orbitted around its art style, while the other game (TP) generally emulated off its story.
Whether the new game will be dark or light... I just don't know. I'm willing to bet it will go back to "light and quirky". With the exception of PH, which was a "light and quirky" game, I'm going to go out on a limb and say it won't matter because it wasn't a big title, and just a handheld sequel.