Guild Wars has a new FAQ up!

Q: I just purchased an unlock pack. When will it be added to my account?
A: Immediately after you add the access key.

Q: Can I use these skills in PvP as a PvP-Only character?
 A: Yes, as long as you have purchased the related campaign or expansion, or the PvP Access Kit for your account.

Q: Can I use these skills in PvP as a Roleplaying (PvE) character?
 A: Yes, but only if you've purchased the related campaign or expansion for your account and have learned the skills from a skill trainer or by using a tome.

Lots of info for the skill and item unlock packs, so check it out!