I've seen them for a while. In the very first announcement trailer which the player plays Protoss, the voice acting is no longer lip syncing as each voice clip matches every word with the lips, mood for the Terrans and the Zerg and bobbing movement for the Protoss. This is actually one of the most unnoticed improvements.

The SCV's afterburner is now colored red and orange according to the April Fools Tauren Marine assaulting a Terran base.

In the concept art, they stay true in size and including every tiny detail set place on the textures. Especially the Tauren Marine's vandalism on his own armor.

The current Zergling have their wings shortened a bit.

The Marine has a new updated portrait according to the savior vs terran video. The Ghost no longer have that placeholder portrait from the Terran Advisor, they actually look like Splinter Cells now. The Zerglings have an updated portrait as well. Both Zerglings and Marines portrait seen on top of the website in www.starcraft2.com are outdated (Which I why I changed my avatar).

The Zerg creep expands asterisk style when the hatchery is built, then once finishing the asterisk, it completes it to a complete circle.

Main Menu may be a placeholder but it shows the bridge in the Hyperion. The "Menu" during in-game is now shorter and placed top left corner instead having it huge and right in your face. The same goes to players that are lagging, it's a lot shorter but still remains in the center.

If your screen is close to a nuclear explosion, but not looking at one pixel of it will reveal sun like rays from that direction. Very similar as to where you're getting hit from in FPS games such as Unreal Tournament, Halo 3, Call of Duty, and such but instead those are red marks on the screen.

If you order flying units to this direction but you want it to fall back, it no longer instantly in a quarter of a second to turn around. Like the Alpha and Beta StarCraft, they will turn around slowly. According to the warp rays and mutalisks.

Units may have different attack animations according to what they are attacking. For an example, the Ultralisks attacks Marines, Vikings, Medics, Siege Tanks and so on by swinging their kaiser blades. But when the Ultralisks attack buildings, it uses the classic attack style from the original StarCraft just more instant.

Unit death animations depends on what attack they're receiving. The Marines have a lot of death animations, from a standard death, shot through the head by Ghosts, cut in half by Dark Templars to even a complete splatter to explosive or from very high damage.

Though mentioned by Blizzard, Sunken Colonies and Spore Colonies returned with a new twist.

The pregame lobby has vastly improved. Not even WarCraft III improved that much compared to the original StarCraft. The lobby in SC2 are divided in three sections. The chatbox is still at the same area but a bit larger. The map name, screenshot, information, or maybe 'Author of the Map' is right above the chatbox. And above that one is a list of players, even though it got a lot shorter, smaller fonts and squishing each line in fits enough for at least twelve players. The "Start and Quit" buttons are at the same spot. Also, the countdown has been removed, it immediately starts the loading screen.

Chatting during the game is no longer on the left area of the screen, it's right above the area where you type and send the message.

Lame.

I hope the area you type your message is at the left side of the screen.

o... o god im about to... ah >.<

Hopefully they will follow through with this and make those different animations for all units...

Not really. If the players are not paying attention to the nuke and the red dot, an the explosion will hint the player where they're under attack. I'm sure you'll only see those sun rays in short distances. It just helps to locate the nuke close by.

I agree. But the left side of the screen is reserved for giving the player messages of what is happening such as "Not enough Minerals", "Can't build there", and so on. It seemed like the warning errors traded spots with chatting.

As if the destroyed section of your base wasn't enough of an indicator.

Lets just hope they shorten them the rest of the way.

Stop hoping. Cause' it won't happen.

Overall it doesn't seem bad. New features that are designed specifially for multiplayer, but now... will it have the "Manditory Host" like Warcraft had?

Yay for realism in a sci-fi game. Also, while there at it, using the alpha/beta stuff, will enviroments be effected. Like trees on fire or flying units crashing into the sea. This might be too much but what about flying units also being able to land and like pick up 1 unit. And then it can attack with it. Like a mutalisk picking up a baneling and dropping them off at areas like bombers or a terran marine, firing from a viking! Oh, the possibilities!

That wouldn't be possible (probably) in the finalized game, however tweaking the editor should allow you to do so.
Create Custom Unit - Mutalisk
Keep settings default, but enable the overlord "pick up" feature
Tada. A Mutalisk that can pick up and dropoff stuff.
Lets just hope this will be in there with compliance to the War3 Editor.

Of course, though that list shows nothing about the small improvements that I've listed, not about the Editor.

The first few things I'll make with the editor, I think, will be little addons to each race that I'll allow. Interceptors that explode on command, a satellite that can burn a target area through fog of war with the proper research (not as strong as a nuke, though.. maybe 300 damage, in an area of 1/2 the radius). Zerg units that slowly get more powerful as time goes on. SCAREE.

Thats all possible. Since the editor is expected to be more powerful than the War3 editor, we can expect more than just a "scale model" upgrade.

There is a quote in www.battle.net, with Karune responding to this question:

Question: "Can the map editor..."

Karune: "Yes, it can."

What was the question to be asked!?

... It's saying the map editor can do anything, since it's over 9000.

They didn't finish the question.

You cannot give an answer to a question that has not been completely fufilled.

You do not have to be technical here, I'm clearly positive Karune stated that as a joke.

Also, a missed improvement I didn't see were the Teams. Instead of Force 1, Force 2, Force 3, and Force 4 from StarCraft and how Teams 1 through 12 in WarCraft III, it's all sorted by Military Companies but by replacing the word company with Team. Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, and etc. Doesn't matter what race you pick, all players sorted in teams that are named through NATO Phonetic Alphabet.