Will the lakes, rivers, and oceans be as simple as Oblivion's or will we see a variety of wildlife? Will we see underwater ruins? Or possibly an Argonian town? What do you want to see?

The lake in new vegas was done pretty well.

Lots of fish, rocks, seaweed, etc etc...
Shipwrecks.
Sometimes loot and stuff on the ocean floor.
Underwater caves.
Underwater ruins.
A few rare, deadly, strong, terrible sea monsters in very deep waters.

Ahh http://www.youtube.com/watch?v=6QOyYxVmMrA

Yes I would really like to see more stuff done underwater. Give us more reason to stock up on some water breathing (potions/spells/scrolls)

FISH
ROCKS
SEAWEED
RANDOM TREASURE CHESTS HIDDEN
The Very Rare Pirate Ship you can loot
Underwater caves/ruins
The Ultra-Ultra Rare Sea Monster

I think it would be cool to see an underwater civilization like Atlantis or something.

an under water argonian town would be sweet. Never occurred to me that you could have those. I'd like to see a lot of detail. Ocean life, more then just rocks at the bottom, sea weed, ruins, statues, fish, ones that attack you and don't attack you, other people swimming (adds immersion), caves, tunnels that lead you from one place to another. I love the underwater world.

Exactly

Thras?

Something like the sunken daedric ruins west of the saltmarsh in Morrowind. One of my most exiting finds in any game ever.

Discovering an underwater civilization would be awesome, but I think it shouldn't be a priority.

I do hope the underwater regions of the game get more attention than in Oblivion, because swimming DID get kind of boring in that game. What's the point of being able to swim at all if there's nothing interresting to see in the water? Not that I'm suggesting they should make you're character die as soon as you get into water deep enough to submerge you like in Red Dead Redemption, no, I'm saying they need to make underwater exploration more interesting. Morrowind was somewhat better in this respect, due to having TWO kinds of underwater creatures (Dreugh and slaughterfish instead of just slaughterfish.) kelp, and the occassional place of interest underwater like caves and grottos and shipwrecks. Still, it seemed a little lifeless, I'd like to see more variety in aquatic creatures, firstly. There also needs to be more interesting underwater environments (More seaweed and such, for example.) and more places of interest under the water.

Meh, human(oids) are out of their element when in water and trying to swing a sword in it is basically impossible, plus Skyrim is freaking cold. Cold waters don't have the same variety of plants and creatures that warmer waters do.

So I don't think they should put a lot of effort into underwater content - maybe something involving the Volkihar but nothing crazy like giant civilizations.

Huge shark-like creatures for the deep sea areas. Small fish, eels, or manta-rays (sting-rays) for the shallow areas. They can reuse the Cliff Racer models for the sting-ray, call it a Sting Racer or Sea Racer.

Or other slow-moving large creatures, nothing too familiar to Earth, more alien like previous Elderscrolls titles. But something scary should be moving down there to keep you on your toes. It should also have some poison or nerve toxin or something that it can spit out in black clouds to convince you to stay away. If you swim through it, you take damage or the affects. Otherwise you can avoid it 3 dimensionally.

Some kinds of waters, to show they are more dangerous, might have a cloud of Pirhana patrolling them. You step in, they chew your body apart very quickly... and yes ... the water should fill with blood to show this. Like a cloud of it expanding from your body. Maybe you need to poison the water to kill these fish, or shoot electricity into the waters to cook them.

I really hope they add life and immersion back into the waters this time around. Why even HAVE water if you're going to make it so boring and lifeless and unnecessary to the game in any way? Water is its own world, and if they do spend the time to make water more interesting, it will increase the overall size of the game by default. Because if you can adventure in the water, battle in the water, seek treasure in the water, and locate secret places in the water, all at great risk while doing so, then you've just made that environment another location to "play" in. Then that would make Skyrim's overall gaming size increase over Oblivion's even if they were exactly equal in square cubic feet.

And if they added an underwater city, or something awesome like that, then you'd have another city to visit, only by navigating the sea to do so. Wow, that would be intense! Especially if there was no light, and everything was glowing in the dark ....

I would expect aquatic dragons.

^ THIS !!!! ^

I've been there. Nice aquarium with a conveyor belt that moves you around it, and lots of interestng stuff on fish. But now it'scalled AQWA.

Last time I checked, there wasn't a lot of inland water in Skyrim, and the only coastline is in the north which I expect may be frozen. I'd be fine with removing any kind of water breathing for Skyrim, as long as they bring it back when they do games in regions where it makes sense.

I'd like a shipwreck with a pirate treasure hidden inside of it

http://img402.imageshack.us/img402/1717/skyrimmapls.png Traced version of Skyrim map from BTS video.

Well, I want various non-hostile aquatic lifeforms to make stuff really colorful, but when it comes to enemies, I want everything they can get of all shapes and sizes.
I'm total freak when it comes to water.
Anyway, krakens, sea serpents, narval-like creatures and much more.

I would liike to see a few shipwrecks about, and maybe 1 or 2 ubnderwater ruins. Not too many though, so it ismore thrilling when you finally do run into one. I would HATE huge sea monsters, as I have a weird phobia of water IRl, and that only seems to translate when I know there are big creepy water monsters in games. running into that huge slaughterfish for the first time about made me crap my pants in OB...

We've had sunken grottos / water-filled dungeons in TES games and they've all been great. What I'd like to see is a normal dungeon that suddenly springs a leak! As the water level rises, you have to find a way back out before you drown. It'd be great if Beth could incorporate some of the tech used in games like Hydophobia to realise this.

I do hope that they add some more interest to the underwater places this time around. I'd love a whole city, but so long as they have two or three underwater baddies, some treasure (callops?), and several underwater dungeons (grottos!), I'll be happy.

Water-dragon, the rarest dragon in Skyrim. You'd have to go so deep you'd need to use a light spell just to see anything, and then you see him.