As a WFRP purist, who will likely change to 3rd edition (I guess I'm not a purist after all!) I have heard rumors that the default setting for WFRPv3 is before the storm of chaos.

The setting of V2 was the most dissapointing part of the game IMHO. While I realize this is an RPG and you can change things to suit your needs, the game material was geared toward the aftermath of the Storm.

WFRP works much better as a "hidden danger", "something is wrong" but the general population is unaware the intrusion of chaos. The storm le the cat out of the bag and made beastmen, mutants, and skaven commonplace.

Am I correct in assuming that v3 is not set during the storm?

Every bit of information that I can recall, seems to place v3 on the eve of the Storm of Chaos. It hasn't happened yet, but there's something in the air that doesn't promise a lot of good. For me that seems to be the best setting. Chaos Cults are stirring, "paving the way" for something big, Beastmen beginning to raid more often, slavers from Norsca who attack the coast more to take workers for the machines of war, bandits who move south because of the "cold wind blowing from the north"...

Wether Kislev falls or not of course depends on you, but the threat is something I can work with.

It's in the same timeframe as v1 through 5th edition WFB; the "brooding, looming, doom" era of Warhammer background. And I agree wholeheartedly; this phase is, by far, my favorite iteration of the setting.