Sources have confirmed to CNET's Mary Jo Foley that the update will continue the Windows 8 name with an extra number, ditching the current codename.
Windows Blue is the codename for the first major update to Windows 8. When it arrives, under the name Windows 8.1, the update will bring new touch options, resizable live tiles on the home screen, and a new way to have two apps side-by-side for multitasking.
8.1 is also set to be the first annual update as Microsoft moves to upgrading the software every year instead of every few years.
Windows 8 RT is getting a .1 update too. RT is the cut-down version of Windows designed for tablets such as the Microsoft Surface, and it'll be updated to Windows RT 8.1 around the same time.
Windows 8.1 is set to arrive in August. Microsoft is keeping quiet about the details of the Blue update, and at the time of writing there's no word as to whether Microsoft will charge for the software improvements.
The latest version of Microsoft's operating system divides opinion with its dramatically different interface, based on coloured squares arguably better suited to phones and tablets than desktop and laptop computers. To get the best from the software, check out our guides to using the new interface and personalising Windows 8.
Is Windows 8 great, or does it leave you feeling blue? What would you like to see in Windows 8.1? Tell me your thoughts in the comments or on our Facebook page.