Microsoft has announced the rollout of its latest Insider Preview from the Windows 10 Redstone 2 Development Branch. Build 14915 is available now for both PCs and phones in the Fast ring.
Today's release comes two weeks after build 14905 was released to the Fast ring, bringing some improvements and fixes.
But at this early stage of Redstone 2 development, Microsoft has said that it's focusing on structural improvements to the OS, rather than on adding new features. As with Redstone 1, which later became the Anniversary Update, Insiders can expect new features to be added later, ahead of Redstone 2's release next year.
However, the company has also warned that these early builds are likely to be more buggy than the latter Anniversary Update previews, so if you're not prepared to deal with issues that might affect the stability of your system, you should consider downgrading to one of the more stable rings, or even opting out of the Insider Program entirely on a temporary basis.