Lenovo has announced the Legion Go S as the first non-Valve handheld to come with an officially licensed copy of SteamOS preinstalled.Valve promises to ship a beta version of SteamOS for users to download and test themselves.The lack of a Windows license contributes to a lower starting cost of $500 for the Legion Go S powered by SteamOS.The Windows edition of the device starts at $730, with additional configurations available in May starting as low as $600.