What kind of things should they say generally?

How the hell would I know?! :bonk:

I don't expect you to know anything.

One particular race should say: "YOU N'WAH!!!"

Bring back Swit From Morrowind. Other then that I'm not really sure I'll have to wait for E3 or later on this year before I give an opinion.

Stop right there criminal scum!
Nothing more

No, tbh I don't know, but I hope that they are going to say more about actual events, like the radio reporter in FONV but bit more variating.
There could also be some rumors which might become an entry into your journal, too example you are walking through a street, see two guys whispering and you will get a message 'Some stupid strangers told about something even more stupid, perhaps you can find the most stupid guy around to get more infos'
Ok, it's quest related
But what I really don't want so hear is always the same two sentences like it was in oblivion and if they do so, it should fit, not one is saying, 'how are you' and the other guy says, 'think it will rain in oblivion today'

"Hey, Terje! How are you?"
"Well, thanks, Eivind, last night's mead at Varg's tasted a bit funny, but after a barrel of two I got used to it and he had to close early since we drank all he had. How about yourself?"
"Umpf, when I got up this morning I was polishing my battle axe, buf my wife managed to foul up my breakfast so it's then that I cut our kitchen table in two, went out, killed a boar or ten and ate that instead. I'm going out later on, chopping up some dragons. Feel like joining?"
"Yes, thanks, I liked how we got 'em running to the hills last week."

What do you think? Something like this?

HELLOOOOO! LET'S DO BUSINESS!

NPCs should have something akin to a personality: mean, friendly, open-hearted, shy, cold ... etc.

This personality should reflect in the things that they say to you and the way the act around you, too.

Example: A compassionate healer may surprisingly heal you, If you encounter him in the streets and you have been very bad injured.

By Azura, By Azura, By Azura.

Snowcrabs. Nasty creatures.

Get out of my way before I have you slapped in irons. Piss off.

I'MA FIRIN MAH... dual destruction spells!

"Seen any elves?"
Collapse in laughter afterwards.

:wacko: -.-' WTF WAS THAT?!?!?

Anyway:
Civilian: Stupid guard says 'What' ?
Guard: What?
Civilian: Exactly.
:woot:

My favorite greeting in Morrowind. I would really like that to be included.

Ive talked to mudcrabs more fearsome than you

I like both these ideas. Nords should be rowdy and brash.

I'd like to see some Nords making rude remarks and threats to outsiders and passers-by, especially toward Imperials and Dunmer. Stuff like "Go home, Imperial swine/pig/dog/whatever" or "Ashlander trash" or something. I'd like some kind of nationalism among the Nords, to help reflect the fact that there's a civil war going on and that they want Imperials out! I'd like to see some proud Dunmer thinking that Morrowind will rise again, and Imperials deluded into thinking that the Empire isn't crumbling. Argonians and Khajiit should be mistrusting towards Dunmer or something. I don't know, I really just want dialogue to reflect the zeitgeist in the game.

I'd like to see beggars begging other people, too, not just me, and getting money from NPCs. It'd be pretty cool to see entertainers in larger cities, maybe Nordic bards or poets in the streets or in taverns, singing about the heroes of old and of the present. I would like people in smaller Nord villages to be a bit weirded out when they see non-Nord characters.

Nord 1: "So Bjarg, how are you feeling today? Harr harr harr!"
Nord 2: "Ssscchh! Not so loud you buffoon, my head is killing me..."

I'd like to see bards playing songs and lute in taverns

ne ne ne ne ne ne ne ne

"I saw some mudcrabs down by the water recently."

Hey there sport, what's the word?

Seen any dragons? AHAHAHHAHAA

*cough*
*snort*
*sneeze*