the AI of the units is definitely smarter, especially melee as Lore has pointed out. Being able to group a near infinite amount of units into a single control group also makes it much easier to control large amounts of units simply by pressing tab to cycle through the unit types. Spell casting is smarter as well generally only casting once despite having a group of 2+ selected so you never "waste" spells (this can backfire if say you're trying to fire off several spells simultaneously but you can always shift click or just mash the spell and click repeatedly). I'd say overall, the micro of the game has been made "easier" in the sense you don't have to single target units to cast individual spells and also not having to control group only 12 units at a time. Don't get me wrong though, your ability to micro will still play a large part in your ability to win close matches so it's not just a roflfest of click attack @ enemybase and just rofl your way to victory.
So, question because I haven't figured it out yet. In WC3, you can click other types of units that are in your current grab and control that unit(s) ability. Can you do that in SC2, or just the hotkeys?
you should be able to do it the same way as in war3. just highlight a large group of units, and click the unit type you want and it should make those your new "selected" unit while still controlling the entire group.
Highlighted a big group of units, and clicking them (in their frame) will only select the one you click. So, tabbing while you have multiple unit types seems to be the best way to do it (if they're not hotkeyed).
Some things though from someone who has been playing a lot of Zerg since I got my key (about a week or two ago):
There has been some very nice improvements to the game itself for Zerg players. Being able to hold almost a limitless amounts of units into one group lets you be able to handle units much easier (which is good, because Zerg usually has larger armies than the opponent).
Also, a very convienient thing is that you can set two rally points for your hatcheries; where your drones will go, and where your regular units will go.
Zerg early game is mostly about roaching hard or going for a fast expansion. The units that T and P can make in SC2 are very hard and Zerg needs to tech hard in order to deal with it. The new M&M:s are very powerful against Zerg and are best dealt with infestors.
Protoss is by far the hardest opponent for a Zerg if he knows what he's doing. Templars are much stronger now, especially vs hydras which can't be upgraded in speed any longer and colosses rip most Zerg armies apart unless you get some good air units like corruptors.
Overall I think Blizzard is doing good with the game so far. They've tried to keep what made the original such a huge success but tried to spice it all up with nice graphics, sounds and UI improvements. The only problem I have is that most early units are too strong. You'd be surprised how strong M&M:s are against Zergs units if you don't have infestors.
Queens 'Spawn Larvae' is +4 every 40seconds. That's in addition to a Hatch's 1 every 15seconds - a very sizable improvement.
Bread and Butter of the Zerg army is Hydra/Roach, imo. Hydras are a little fragile, but can put out a ton of damage - Roaches are a little weak on the dps but they're tank as - getting up to 5 armour. Also, the range differences [6 for Hydras and 3 for Roaches] mean that your tank's up the front taking the damage.
At high level, you can micro damaged Roaches to burrow - only the damaged ones. The majority of players don't have the micro to be doing that - especially when other things will provide a greater return. Not to mention the multitasking of keeping macro going while micro'ing your army in a battle.
Mutas are a good midgame harass unit - especially for maintaining map control as many players are unwilling to move out when their base is likely to be attacked moments later. Mutas die extremely easily though, so it's a good idea to exploit their impressive movement speed to move around and get into a better position for later use.
I would love to help out with any future SC2 Beta videos beyond the showing all the new units. When your done with Terran that is, and that will be an interesting video to go through everything.
Right now most matchups include the same tactics that I've seen. I got ranked Platinum 1v1 only playing Protoss, but I used the Random setting after a while before the rest and used to be Gold League.
I think it would be somewhat interesting for videos to showcase matchups and how well things match up against other things. Especially a good representation of hard counters like 6 marines and 3 hellions vs 3 roaches.
Beyond hard counters though I have seen things used very well, from Ravens Seeker missle, to Colossus dropped on a mineral line via a Warp Prism. I've seen some varying tactics PvZ that I held out against for as long as possible but ended up being unable to win against in the end. Muta/ling being the one that is truly difficult to fight against. The truly effective nature of Sentry's forcefield.
I'd love to help, or simply get some more people on my beta friends list, the people I've usually played with have been busy, or lost some interest. Send me a message some time in game, Shrapnel.nukeo.