Valve will begin shipping Steam Machines and Steam Controllers to beta testers this Friday, Dec. 13, according to a post on the Steam Community site.
Valve announced in September that it would send prototypes to 300 testers, and those receiving Steam Machines will hear from Valve today.
"The 300 selected beta testers are being notified today (at about 2:00 p.m. Pacific Time) that they'll soon receive Steam hardware and SteamOS for testing," Valve's Greg Coomer wrote. "Each selected user is also being awarded a special badge on their Steam Community profile, indicating that they're a beta participant. In addition, a number of games that run natively on SteamOS are being added to each selected user's library."
Coomer also said that "regulatory hurdles" forced Valve to limit the hardware beta to the U.S., despite its desire for worldwide distribution.
"This was not our original plan, and it means we can't collect beta feedback from Steam customers world-wide, which is pretty unfortunate," he wrote. "All things considered, we're sure it was the right decision, because the alternative was to delay the whole beta beyond the point when we'd be able to incorporate any feedback into the 2014 products."
You can learn more about Valve's upcoming hardware and software expansion in Polygon's coverage of Steam Machines, SteamOS and the Steam Controller.