This info was just leaked on the twitterverse.
I was honestly really hoping for a copy of Fallout 4. At least that will be one of the few exotics no one has Xurned still.
EDIT: Lord Malak has reminded me that Xur will also be selling the Illuminati engram.
-
All I see in these forums is people blaming about how they earned their Half-Life 3. You didn't EARN anything. It all random. It's all the work of RNGaben. So shut the blam up.