Is it like SC1, example : Having 3 science vessels, clicking Irradiate and clicking to one unit will result in all 3 units to cast one irradiate each to that unit. Or Like wc3, having 3 units that are the same, casting a spell will result in one of those 3 to cast it, casting it again will be another unit casting the spell, a third time will be the last one again, a 4th time will be the 1st one again, considering he has mana?
Blizzard is implementing smart-casting in SC2. It's in one of the Q&A thread but I'm not sure which one exactly. You can do a search for it. That means, casting will be like Wc3.
The two spells i'll miss are Irradiate and lockdown with smart casting, and Restoration too The biggest beef i had with lockdown is the annoying way you had to cast, and ghosts would die before you could lockdown the enemy
I believe in Starcraft 2 that if you select a bunch of units and click cast, only one of those units will cast. However, if you hold shift and click, you can cast again and again. In other words, select three ghosts, click snipe, hold shift, and click on three enemies. Boom boom boom. That's how it looks in the Terran preview video.