Ok...just what in the hell is this?

Go to the bottom of the page.

A list of serial numbers is at the bottom of the BWU, and if you highlight them with your mouse, more of them appear.

The letters and numbers are shown here:

KPXW2-3MWC2-23C2Y-RXGCR-Y27CZ
XC79T-D2K9D-JCWGR-Y7WF2-WJFFZ
2YDR7-9GVYD-TG62T-J466C-3G6TZ
Y3DKP-9M7HV-HHRD4-HPCYC-32J7Z
CGY63-9DJJW-2PRJT-HD924-PJXGZ
DHT42-R2KJ4-6477Y-CJMQM-JD42Z
KDVP2-XFTK2-V42QQ-CPKWG-KM7WZ
WT7K4-P49MY-R7JKK-MH3GP-7JJHZ
2T7V4-Q9CJH-QV42K-RJM4C-27F3Z
RT23V-JCH66-C6R6V-797VP-TCWKZ
KFF63-RQ3YK-3QDMM-7MGYF-9X4DZ
3FTXY-F9FJ6-RPG7D-9HT3J-MHH4Z
4Y363-KJ3QP-2K3QP-3JHFT-THK4Z
QTRYR-7H2PX-R2JFY-67VGF-D96KZ
62HGG-9THTV-JVM6F-7VYJX-QXVRZ
TTRTQ-9FPCY-WFPCG-MCPW3-4XX3Z
HR93V-24TGR-DYP44-XTJGM-GJ4FZ
HCCXH-HDHT2-79PGX-XH3HK-224HZ
CM943-GMXTC-2JRHW-F2P6V-DGHPZ
X9HFX-KRGQ9-9XM3H-QF63H-FPKMZ
6RKXH-VY7J4-46X47-QMRCK-JDRPZ
6H79G-WHPCW-JYCVC-RKWDH-9622Z
MVJ3G-2HMFF-DJVKM-C9XCX-9K3TZ
P4K7W-TMDWP-Q4GD2-F92HQ-JQM6Z
CRWYY-727FF-YWY4J-FYKVV-K69RZ

Codes for the Defiant Map Pack (most likely)

> Codes for the Defiant Map Pack (most likely)

That’s exactly what they were. People posted in the Bnet forums about it.