In particular, Microsoft is working on bringing robust eSIM support to Windows 10 in its upcoming Redstone 4 update, as well as power-management improvements. As first reported by ZDNet (via WalkingCat), details about the ongoing work and roadmap were revealed by Microsoft during its recent WinHEC Fall 2017 workshop.
In terms of LTE connectivity, Microsoft is working to make the process of activating an eSIM more seamless. With improvements coming in Redstone 4, users will be able to download profiles from the cloud, attaching their device to their carrier's mobile data plan without the need for in-store activation. This will make it easier to get up and going with LTE connectivity after unboxing and setting up one of these Always Connected PCs.
Microsoft is also extending this to an Enterprise eSIM feature that will be released as a pilot in Redstone 4. According to presentation slide from Microsoft, this feature "allows enterprise to bulk purchase subscriptions" from mobile device operators, then use mobile device management services to automatically provision connectivity across devices.
Aside from its eSIM work, Microsoft is also planning to work with Intel to certify that devices pass tests related to Modern Standby, which manages background activities. The goal is to get Modern Standby enabled on desktops, not just mobile devices.
According to the WinHEC slides, Microsoft is planning on getting these features working in time for the Release of Redstone 4. The update is currently in testing with Windows Insiders, and it's expected to be released sometime in Spring 2018.