RG Live WotLK 3.3.5a

"So, what my tests showed:
Haste is calculated on initial FS-cast. LvB does increase the duration, but won't change the haste-value. (tested once without buffs and then with a shitload of haste-CDs)
Same goes for spell power.
It does work with BL and other CDs, too... in the following way:
Although the wording implies different, it is not really fixating on the number of ticks.
It will always(?) try to grant equal to or more than 6sec duration on FS.
So even with a shitload of haste-CDs (1sec FS-ticks, or rather 17 ticks in 17 seconds, thanks to 2 LvBs) you'll have ~3x the ticks you would otherwise have... just maybe sometimes one less.
So instead of the 6sec it would normally have had, those two LvBs together added ~12 seconds to the DoT, making FS have nearly three times the normal duration."
(Quelle: https://www.mmo-champion.com/threads/699323-Elemental-Shaman-new-T10-4P-Question)