A fan has made an interesting discovery; Steam has registered some Xbox subdomains.
These subdomains include the very clearly Xbox related xbox.steamgames.com and xbox.steampowered.com. Our source can only speculate on what these domains are for, if they are planned to be used at all.
Reddit is sharing their theories on what this could possibly mean. Yvese believes this will allow Xbox account owners to connect their accounts to Steam. This is the top comment on the thread, and for good reason. Valve made such arrangements with the release of Portal 2 in 2011 on Steam and PlayStation 3. Portal 2 remains the only Steam game connected to a console, offering features like cross-platform matchmaking, gameplay, friends, chat, Steam achievements, and even Steam Cloud save.
However, dostro89 points out that Microsoft is one of the few companies positioned to compete with Steam on making a PC storefront. Sekular points out that this looks more like an action by Valve, than by Microsoft, since they own these domains.
As Yvese points out, we may learn what this is in the upcoming Xbox One and Windows 10 gaming event later this month.
You can read Gameranx’s prior coverage to see that there is no precedent for Microsoft and Valve working together for Xbox and Steam. Microsoft has already gone on record that Windows 10 and its App Store is not competing with Steam. On the other hand, they placed limits to disallow Windows 10 installs on Steam Machines. Valve has been critical of Windows 8, and joined the Linux Foundation on the way to launching their Steam Machines initiative.