For more details, see Always Connected PCs enable a new culture of work (Windows Blog)
"The obvious question is why do these devices even exist? Microsoft has worked with Qualcomm to create these “always-on” PCs so that they’re always connected to LTE connections, and work more like an iPad than a traditional Windows laptop. That means you open the laptop up and it should instantly resume, or you close the lid and never have to worry about the battery draining. These devices should have battery benefits and the type of LTE connectivity that we haven’t seen regularly in Windows laptops.
HP and Asus’ devices will include Windows 10 S, designed to only run apps from the Windows Store, but users will be able to upgrade to Windows 10 Pro free of charge (for now) to get access to the full desktop apps. Microsoft has natively compiled Windows 10 to run on ARM chipsets, so all Windows processes, Edge, and the shell all run natively without emulation. Microsoft has also looked at the top third-party desktop applications and natively recompiled a set of system DLLs that they rely on to ensure performance is solid."Microsoft launches ARM-powered Windows 10 PCs with ‘all-day’ battery life - The Verge: