all the people doing theorycraft and stating alacrity causes us to use more energy make me mindboggle.
if you have to cast a heal, casting it quicker is actually optimal in both pve and pvp. if you are in a vacuum standing in one spot chain casting, ok your point has merit. if you are in an actual boss fight and oh **** had to move and now cast a heal on that guy who is almost dead, the quicker cast could make or break the situation.
not to mention quick casts can free up seconds to toss a dart or grenade or autoshot (w/e it's called) on said boss.
don't get me wrong, i ripped all the alacrity enhancements out of my gear and replaced them with power/surge but still don't dismiss it as a moderately useful stat.