I think your going to find that Arcane has been passed up by TTW FB, and on the LONGER Ulduar fights, the mana efficiency of FFB maybe even puts that spec ahead at times.

Second, there is a search function, it's really cool, and can help narrow down what your looking for around here.

Scorch: That is correct.
Vitality: 15 Spirit v 12 hit+12crit...no. Spirit only converts over at 55%, so 55% of 15=~8 crit rating.

This is more or less what I meant to imply, as there's really no reason to move unless you need to move to get out of something (which implies that if you stay where you are, you are going to die). But take Heigan for example. Tuskarr's Vitality doesn't help you on Heigan fight. The only things you can cast as Fire is Scorch, Fire Blast, Living Bomb, Hot Streak, and Ice Lance. There's no time for Fireball or Frostfire Bolt and Tuskarr's Vitality won't change that. Similarly, Tuskarr's Vitality never helped on Thaddius, because you can just blink across.

I used blink on Grobbulus as well. Instead of constantly moving, I would run inbetween global cooldowns (after using Hot Streak pyro or casting Living Bomb) and resume casting afterwards. When Grobbulus reached a distance at which I could not refresh Scorch, I would just blink ahead. Same thing for when I was targetted with slime, I would run out and blink back in.

In short, the time I spent running vs the time I spent in stationary DPS positions (and used blink instead of running) far offset any increase I would have gotten from a movement speed bonus. Consider that hit rating, after hit capped, is valued at something like 3.5-3.7 DPS per 1 hit. Crit rating is ~1.5 (slightly higher for FFB). That would mean Tuskarr's Vitality would need to be adding 61.2 DPS. That seems overly high (in the hit department), and is likely because the relative stat value for hit isn't exactly accurate when hit capped (as the warning in Rawr says). Nonetheless, even if hit was valued at 1.7, same as spell power, Icewalker would still be contributing 38.4 minimum.

I'm not sure then how 8% could match that at 4 seconds of movement per minute, because is that assuming zero DPS during your time running? For instance, if you were to run and calculate the amount of DPS you would have gotten if you were stationary, and then calculate the amount of DPS you gain by casting something like Fire Blast while running, then you need to factor in the global cooldown of Fire Blast. That would lower the DPS contribution of Tuskarr's Vitality and increase the DPS value of Icewalker. And the argument is that you couldn't have been casting anything else (except for Fire Blast, or Living Bomb, or Hot Streak Pyroblast).

The post in question was made by Roywyn. Clearly he has a point, as everyone does. But I think Blink should definitely be taken into account here. You would need to factor in the time it takes to run 20 yards, then run 20 yards at 8% faster speed. I suspect it takes more than 1.5 seconds to run 20 yards. Naturally, that isn't saying that you'll always need to run 20 yards to get out of the fire, but plenty of fights where movement is in question, Blink can be pretty grand, and clearly beats running. This of course gives favor to Icewalker enchant.