First of I'd just like to say thank you very much to leatherpatches and those who made the other mage-related guides. You've helped me a great deal, particularly with improving my kite-grinding.
Now, to business.
I've seen the problems with Frostbite and kiting far too many times; my first attempts at kiting, many levels ago, had this talent at the time and they all ended in disaster. But I have to wonder: considering how slow mobs move when you have Permafrost and Imp. Blizzard maxed out, they remain within the circle for quite a while. With Frostbite maxed as well, is it possible that the number of falling bolts could have any good chance of freezing an entire group of mobs?
I think it's worth trying out, though chances are it won't work.
A build such as this, at L42, with all the necessary talents plus Frostbite, is all you'd need. If it could work, at higher levels (such as 50+ when you get the Elemental) it would help a great deal (even more opportunities to freeze is always good). And let's face it, if you're not grinding Frostbite is a great talent.
Or maybe it's just wishful thinking on my part.