Neowin has reportedly been able to get their hands on a presentation to one of Microsoft's partners, which includes some information on when Windows 10 Mobile will be launched for mobile devices, suggesting that both the enterprise and consumer editions of Windows 10 Mobile will be launching late next quarter.
According to Neowin"The spokesperson was a bit less enthusiastic though, hedging the company’s bets and saying that the OS should come in October, or 'possibly as early as September'".
Windows 10 Mobile is expected to be available late September or early October.