Bit of clarification requested on:
Change: Windows Update KB2918614 adds support for wide-screen Windows Logon images
Does that mean that we get logon image for other displays as well, or is that merely resolution improvement or something? Tried to look around for hints of what this could be in practice, seems that I'm blind/completely missing it.
It unfortunately doesn't enable logon background images for multiple monitors. It just fixes up an old width limit, which I believe was 2560px. Now it works on wider monitors, like 4K monitors, or NVIDIA Surround setups