Nostalrius Begins - Quality wow vanilla realm (1.12)

Imbue the Shaman's weapon with wind. Each hit has a 20% chance of granting you 2 extra attacks with X extra melee attack power. Lasts for 5 minutes.

That aditional damage never give up, on my windury weapon says give 348 additional extra attack power but didnt counts on my stats.

-without windfury buff
http://prntscr.com/85n0bh

-with windfury buff up
http://prntscr.com/85n1c0

Same ap and damage with windfury up. i am right?

the extra ap is just added for the 2 extra attacks that proc from wf , it's not added to your character permanently

In 1.10 or so it did add the plus AP to your char profile, but after that they canged it.