Windows Update 8.1 Arrives To MSDN April 2, Windows Update On April 8th Patch Tuesday
Those dates come from Paul Thurrott, owner of Supersite for Windows, who posted the information on Twitter. While that doesn't qualify as being official -- it's not coming directly from Microsoft, in other words -- Thurrott is generally on top of such things.
Based on supposed leaks of the update, one of the rumored changes it will introduce is enabling the boot-to-desktop option by default. This is an option that Microsoft added to Windows 8.1, but it's not turned on by default.
It could also include the ability to pin Metro apps to the desktop taskbar, dedicated search and power buttons to the Start screen, an on-demand taskbar that you can call up from anywhere at any time, Jumplists for modern apps, a OneDrive (formerly SkyDrive) icon on the taskbar, and more.
There still hasn't been any mention of Microsoft bringing back the Start menu. The Start button made a return to Windows in Windows 8.1, but not the Start menu.