I haven't tested Starcraft 2 so i don't know if this is a feature or not, but i always find it incredibly annoying to only be able to move 12 units at a time (16 in Warcraft 3). In a real army, the whole army can be mobilized at once. I have to hot key groups of 12 to get my army really mobile. Why not have the ability to control an unlimited number of units? Or if not that, be able to send all of your men with a feature from your command building (an INVASION button, or a mass assault button that sends all your troops to a location). This would be so much easier, and since the computer can be programed to send over 12 units at the same time, it wouldn't be unfair.

Opinions?

I figured i should throw these in too. Some are just ideas that i thought of, and probably wont work.:

1) Hydralisks have those awesome scary scythes on their arms, but NEVER USE THEM except for cut scenes. How about if units close in close range on hydralisks, they use their claws! Even if theres no difference to damage, it would look super cool.

2) Marines with attached grenade launchers as an upgrade. Limited grenades (like spider mines).

3) The ability to refill spider mines by going to the factory or by purchasing them.

4) Dark Templars only cloak at night.

5) Ghost that can use psi to snipe for a one hit kill (I think they have this in SC2, but i wasn't sure)

6) Running and gunning (shoot while moving)

7) the ability to let units sleep to slowly regain health.

8) being able to let units out of vehicles, and go to other buildings to become other units for a cheaper price. If i have a tank for 150 min, and it is about to die, i can unload the 2 people in there and take them to the barracks. They become marines for 20, instead of 50. Same thing with flying units.

9) the ability for units to take cover behind walls.

10) Being able to buy a leader so unit upkeep isn't so high, or so upgrade prices drop.

they already have(that's certain) I think you can get over 40 units at a time not sure but I am sure they have upgraded it to a lot more check it out on the battle reports(youtube)
hope I have helped you.

If it is possible to select more than 12 units, then we will not see multi selection hacks as soon as the game comes out ... It would be fair if everybody could select more then 12 units, not only the hackers ...