Yes, the current Green Man Gaming (GMG) discount works until a little after this weekend (actually until Monday, July 1st, 3 PM UST, which should be 11 AM Eastern, 10 AM Central, or 8 AM Pacific time) but I wouldn't wait until tomorrow!
The code is:
GMG25-BAWQB-8UQWG
for a total price of $20.25
In addition, if you are new to GMG and don't have an account yet, you can also use the "Friend Referral" mechanism to get
$2 credit (for you and the referrer each) by creating a new account, for an effective price of
$18.25.
If you do not currently have an account with Green Man Gaming, you can:
1. Enter the link <
http://www.greenmangaming.com/?gmgr=liligaqa >
That one is the link for me (you can use someone else's if you really want).
If you use the link, it will just take you to the main page and doesn't *appear* to do anything. (But it creates a temporary cookie that only works if you immediately create an account).
2. You then create an account (apparently it doesn't work if you already have an existing account) with Green Man Gaming with the "Log In / Register" option.
3. Add Brave New World to your cart and enter in the promotional code (so the total is $20.50).
4. After you check out, you should end up with a credit balance of $2 (for using the Refer-a-Friend promotion).
5. The BNW key isn't released until the game is released. You can find it by entering your GMG account, select the "Games" category and under the "Steam Games" heading. It should show BNW and a space where the key will appear when it is released.
Even after the current code (for this weekend) lapses, you can still use the "Friend Referral" process (listed above) if you purchase from GMG (using no code, or another future code they promote) for the $2 credit.
I bought from GMG the first time last year with G&K, and the referral process helped accrue a small amount of credit that I just used to help buy BNW (and those who used the referral got the same amount of credit). Let me know if you have any questions.