Don't spec destro for PvP. Its not that useful in BG's and useless in arena.
The one setup you forgot, I find the most useful (for any other spec). Full dreadweave for extra stam/resil and set bonus. Felweave is ONLY useful if you want the 35 resil. Besides that the crit is absolutely useless. Any spec you choose is only going to give you 10-15% crit chance in Felweave gear and you will never crit against anyone in any type of PvP gear. So basically you lose spell damage, stamina, and resil, for nothing.
Edited, Apr 13th 2008 10:50pm by Tugnus