Yes, it is one of the most broken spells in the game, as a level 2 spell and immediate action, you can negate much higher level / more powerful attacks and waste standard actions. Notably at the earliest levels it is gained, unless a creature has TWF, haste, or other means of making two attacks in melee, you can actually completely shut down an opponent's offense. At higher levels, level 2 slots are cheap an plentiful, the benfit of the spell effectively scales along with the dangers thrown at you, and...the one time I had a high level sorcerer with it (the rest were sorc/warrior gish builds), he reached level 15. I was pretty forthright about how good the spell was: "If I had used up all my level 2 slots, I wouldn't even hesitate to blow a higher level slot to use it again if needed. Situationally, it could be better than my level 7 spells anyway."
When I say, "when all splatbooks are added in with core, Sorcerer becomes the equal of Wizards and CoDzilla," spells like Wings of Cover are a significant part of that belief. (Other big factors besides obscenely good sorc-only spells: The large amount of ways to add charisma to other rolls; the gradual easing up of metamagic hindrances on the sorc -- the PH2 variant, the Complete Mage's Rapid Metamagic feat, etc...; the accruing number of full casting or near-full progression casting prestige classes, which benefit wizard as well, but are even more useful to the sorcerer, who has no class features to lose)
/rant
