How does the in-game store "pre-order" of GWEN work?

Let me be more specific:

If I buy the $5 "pre-order" pack for GWEN in the online store, I know I'll get access to the bonus content (weapons, sneak peak, etc.), and I know that the $5 will come off the price of GWEN in the in-game store, but what I don't understand is exactly how the in-game store transaction for the purchase of GWEN will take place.

Since it says I'm "pre-ordering" the game, will GWEN be automatically added to my account when the game is released and my account automatically billed $34.99?
Or will I have to physically purchase GWEN in the in-game store myself after it is released?
The latter seems more likely, but how exactly is that "pre-ordering" the game?
And if the latter is indeed the case, couldn't I buy the pre-order pack in the in-game store but then buy GWEN at a retial store?

So I'm not really "pre-ordering" GWEN in the in-game store, I'm simply purchasing the pre-order key with the bonus weapons and sneak peak, correct?

the later is how it will work. By doing what you suggest in the former, that would be like you handed your credit card to them and gave them carte blanche permission to put anything on it. They don't know if your situation has changed etc or when you intend to actually buy it. All the preorder/prerelease does is let them and other businesses offering it get an estimate of how many copies they will need. If EB only sold a single package at store X, do you really think they'd bring in a huge number of them to that store?