There's no sign of a pre-order being made available on Steam, yet. However, a pre-order page has been spotted over at the EB Games website. I've just spoken to Brisbane's flagship EB Games store, who have told me that an in-store pre-order requires a $30 deposit and they're taking them now. However, beta cards won't arrive in store until Monday the 25th or Tuesday the 26th, at which case they'll be calling pre-order customers to come and pick them up...
Now, assuming this game winds up being no more expensive than $60 on Steam, you could pre-order the beta card from EB Games and then cancel your pre-order after you've picked it up. You would have essentially have just 'bought' beta access for $30, and paired with the price of the game on Steam, paid no more than what you would have for a boxed version at EB Games. Given my enthusiasm for the game, I'm very seriously considering this.
The Steam pre-purchase was made available around 14 hours ago. And previously no specifics had been revealed about the beta in relation to physical pre-orders.