You know, I haven't yet ordered from Knitpicks, but just from everyone's input here on how awesome their CS is, I wouldn't hesitate. And now, their answer to my question:
"This hasn't really come up before, but I don't see why we couldn't honor our original policy. I will need the name and address of the original customer, just so we can cross-reference the original order for accounting purposes. I will also need your address, to locate or set up an account. I will put comments on both accounts that explain the situation. Everything should work out just fine.
Knit Picks Customer Service
How awesome are they?
And seriously, I can't believe I'm one of the first to ask this of them!!