I'm using the latest build of Windows IoT for the Galileo Gen2 (9600.16384.x86fre.winblue_rtm_iotbuild.150309-0310_galileo_v2) and writing Wiring applications in VS2013Pro.
I want to start building network connections, but the first parameter I need to specify is the MAC address. The board came with a MAC printed on a sticker on the mag-jack, but did it get written to the onboard flash somewhere? Were do I find it from inside my Wiring/IoT app?
I would suggest you to contact the Microsoft team in charge of the Windows IoT image, we support the Yocto image, so in this case I believe they will be able to provide a more accurate answer to your question. Here's the link to their community, Community – Windows app development.