What? No, I still love you, [Parachute Cloak]. You know I'd never give you up. But, you have to admit... you're kinda useless indoors. Oh stop crying, it's not like I'm breaking up with you. Besides, you're not even sentient! How can you possibly be upset when you have no emotions?
OMG, emo much?
Where was I? Oh yes, new favourite toy. Behold the awesomeness that is:
Look familiar? If you've played a mage at some point since 2.0 went live, it should.
That's right; Frost Grenades are a mini ranged Frost Nova in-a-can. Well OK, it's less a can and more of a highly volatile explosive device with a hair trigger, but no one said Engineering was without its risks.
But what about them makes me love them so? For those who aren't aware, without talents or set bonuses (bonusii?), hunters cannot trap a mob back-to-back. The problem is that our Freezing Trap lasts for 20 seconds, but all our traps have 30 second cooldowns. This is why good hunters pre-trap whenever possible: drop the trap early so that the cooldown can at least partially clear. That way, you can drop the next trap sooner; in extreme cases where the mob resists, you can drop your next trap immediately.
But no matter how careful you are, there are going to be times when things go, excuse the Klatchian, librarian-poo. That is, your druid tank accidentally pulls by Moonfiring your trap target, or the first trap resists and the cooldown isn't up yet, or some silly paladin didn't watch where he was dropping his consecrate.
None the less, hunters of all specs have a few tricks up their sleeves for times like these. Beast Master hunters can use their pet's intimidate to root the mob for a few seconds, Marksman hunters can Scatter Shot, and Survival hunters have increased trap duration and so much damn agility that they can practically evasion tank . That's not even mentioning Concussive Shot and Wing Clip kiting.
But some times that's not enough. Enter the Frost Grenade. This puppy will root the mob for five seconds (which is half of the difference between our trap durations and cooldown,) giving you enough time to get to distance and drop a new trap.
In a Steamvault run earlier tonight, these things got used on four occasions. Twice was for keeping a mob occupied while I got a new trap ready, once to save the healer from a mob that broke free of the tank , and once on those bloody gnomes. I hate those things; hold still and die!
As a bonus, the materials for making them aren't too expensive; 1 Primal Water, 1 Mote of Fire, 2 Motes of Earth, 2 Netherweave Cloth, 10 Fel Iron Casing and 10 Handful of Fel Iron Bolts (80 Fel Iron Ore in total) will net you 50 grenades. They're made in lots of five and stack up to 10, so I'm keeping a stack on myself and one in the bank.
If you're a hunter and an engineer, I strongly suggest you check them out. Best of all, the recipe is taught by your friendly neighbourhood master engineering trainer (335 skill required.)
 I do not recommend or endorse hunters attempting to evasion tank simply because they have agility coming out of their eyes... Now there's an idea for a WotLK talent: agility eye lasers!
 Admittedly, the mob was nearly dead anyway and I kinda accidentally ended up rooting it right next to the healer. But it's the thought that counts, right? Right? Guys?