ARGH. At first I thought you could get the Moonwell Chalice immediately upon entering Firelands, but no luck with the vendor for 31 days, apparently.
There is a full month-long chain of dailies to unlock her and the other two vendors.
To unlock the first vendor takes 31 days; to unlock all three takes 41 days.
But for your parting gift, I give you the Nightweaver's Amulet, which you can bag essentially immediately after hitting the Firelands.
And now back to the item you can get 31-41 days from now.
I've been trying to update the pre-Heroic gear list for 4.2, and it's been a pain, in part because Wowhead was misreporting Valor Point items as Justice Point ones. I thought I was about to get insane legs, pants, chest, wrists, and rings. Now, not so much.
That said, check this item out. I like the Gale of Shadows as much as the next guy, but this item is
Moonwell Chalice - Item - World of Warcraft:
Binds when picked up
Requires Level 85
Item Level 365
Use: A small moonwell appears, blessing you with 1700 Mastery for 20 sec. (2 Min Cooldown)