From a game design perspective, the only difference is the aesthetics. They function identically.

We know a ton. That gameplay revealed a lot.

Next to the original Legend of Zelda Windwaker would be my favorite so it fits me perfectly =)

Look online. There are anecdotes everywhere. It's a peculiar thing with the Zelda series.

I think you've read too much into it, but it's been obvious for a while this would be the most 'open' 3D Zelda. This is a game with at least 11 months of development to go, and I think the video was deliberately restrained to display only a couple of key mechanics.

I think given the complaints levelled at Twilight Princess and Wind Waker, there'll be more to do over-world wise in Zelda U than Wind Waker, but I wouldn't be surprised if it is similar to the island system in that there are points of interest (of varying complexity) to discover. I don't think these'll be evenly spaced out, and I think there will be more of them than Wind Waker. I think the key point about Zelda U is that it will be more challenging and fun to discover these areas: you won't see an island as the only point of interest, you'll see a certain feature (like a tower in the quick demo, or that gateway which seemed to indicate a dungeon was near by) in the landscape that you can go and investigate. Hopefully they'll take some cues from Skyward Sword in that these areas won't be easy to get to, even once you've found them. I'd hope parts of the overworld are still a challenge to navigate.

I'd also like to see 'hidden' dungeons, like in the first games. Maybe main quest dungeons will be easier to find, but have some secret ones for players to find and explore. Make these as sophisticated as the main quest dungeons, rather than the simple cave/chamber type areas you get in Wind Waker, for example.

I don't agree that this is Wind Waker on land, but I think there are points of comparison. Ultimately I think more cues are being taken from the original Zelda, but it's obvious the influence of more recent, 3D Zeldas will be quite prevalent in this game.

You know a ton about a demo build of a game with at least a year of development time to go.

I hated Wind Waker but I reckon I'll love Zelda U.
Its rendition of Hyrule Field looks vastly more interesting than the dead-boring sea in WW.

I didn't like the sailing much but I will love riding Epona on land as there is so much more to land than an ocean

Nice monologue, but it depends on what's there.

Wind Waker's sailing was tedious because there was nothing to do for minutes on end on a flat blue field of nothing. The HD version anyway fixed some things because of the Swift-sail which besides the added speed also eliminated the need to redirect the wind, something that originally slowed down things greatly and hindered freedom. I remains a big ocean though, literally, of nothing.

Zelda U at least got Wind Waker beat in that part; riding around on a horse through a varied landscape is loads more interesting than sailing in a straight line.

The sailing wasn't even the only (or biggest) problem I had with Wind Waker though. It was way, way too easy. Moreover there were too few dungeons which were also too short and again too easy. These things were adressed by Twilight Princess, though also still easy it wasn't that easy, and Skyward Sword (and even the handheld titles) so I'd expect the line of progress to continue.

I loved Wind Waker, sailing and all. It felt like I was actually sailing a huge ocean.