I don't think anyone asked the most fundamental question of all: does this spell actually have a casting range or does the OS "drop" the cloud, in the same way the OL drops creep?
If it's the latter, that negates a lot of the ideas you guys have been having (like casting clouds over static defenses to be able to use zerglings more efficiently, or doing the same over a group of marines and running banelings at the).
I think it would be incredible (for the zerg player

) if the OS could cast this from a distance, but on the other hand, if the OS has to be on top of the region that's going to be clouded... it seems to be a bit too much of a defensive spell because that means it would almost always be cast over YOUR units, and not your opponent's. It also happens to be a spell reserved to rather small battles and relatively early game (no flying units around).
For example, even if the OS could cast this from a distance, it would be useless against a "beyond early-game" terran bio army (medivac) or a protoss army (obs). And don't forget it's a T2 spell, and all races opposing zerg will probably be going for detection much faster because of baneling traps.
It still sounds like a totally awesome spell though
