So, in my last thread I mentioned Xenoblade X could be the most ambitious title on Wii U, and people have not been shy to let me know that it isn't, Zelda U will be. I'm just wondering how? 

Let's look at what Xenoblade X is giving us:

More realistic graphics

Full voice acting

VERY few load screens (in fact the people I've watched that's played it say the only real load screens are when fast traveling and before cutscenes)

Online Multiplayer

Fully accessible massive world (you see it, you can go there) with day/night cycle and dynamic weather

Customization of a party of characters and vehicles.

Armor and weapon crafting ala Monster Hunter, but gear can be worn and seen as "advertised" to allow shops to release new equipment

So what's LoZ Wii U going to do to compete with that? 

I don't know. I don't know anything about Zelda U since E3 2014. We need news about it soon. Also, didn't Monolith studios say that they wanted to help developing Zelda U? Maybe most of those things you said will be present too (except full voice acting, Link grunts for the win).

It will have bigger bosses, larger boobs, it will have a special headset that lets us taste the graphics...

HOW THE HECK AM I SUPPOSED TO KNOW!?!

An opinion that would hardly equal more ambition.

We don't know anything about the game, so... I guess that they'll try to change the concept of "open world", so I expect different gameplay mechanics, different level design and a revolutionary concept. It's hard to say what they're thinking though, let's wait and see.

- not feeling like an pretty cheap to make random mmorpg from 2007 in terms of gameplay.

Which random cheap MMO gives the player on the fly weapon and skill pallet changes and mech that can be used at will?

And it isn't like we haven't seen Zelda Wii U's battle mechanics anywhere before, lol.

Silly d21lewis, that's the recipe to Bayonetta 3!

If we are only looking at the game through the aspect of gameplay, then yes it would be all it needs. But how much better, and looking at the game as a whole in terms of ambition and not a single aspect would be more fitting when saying a game is more ambitious in general.

*edit* Also, none of this is opinion:

More realistic graphics

Full voice acting

VERY few load screens (in fact the people I've watched that's played it say the only real load screens are when fast traveling and before cutscenes)

Online Multiplayer

Fully accessible massive world (you see it, you can go there) with day/night cycle and dynamic weather

Customization of a party of characters and vehicles.

Armor and weapon crafting ala Monster Hunter, but gear can be worn and seen as "advertised" to allow shops to release new equipment

Do we know that Zelda Wii U doesn't have:
-Full voice acting
-very few loading screens
-Online Multiplayer
-Fully accessible massive world (remember Aonuma's words: as big as Kyoto?)
-Armor and weapon crafting?

We have seen the game last time almost a year ago! Things can change.
Plus Zelda Wii U has been development for a around 2 more years.

I think Zelda Wii U could be far more ambitious. That game is in development for 5 years now.