Seems, Windows 8.1 update 1 release has been pushed to April now. It was earlier supposed to ship on March 11, but according to Mary Jo Foley, it may now arrive on 8th of April.
She notes,
I’ve heard from two of my sources in the past week that Microsoft’s ship target for Windows 8.1 Update 1 has shifted from March 2014 to April 2014.The idea remains to use Patch Tuesday to distribute the coming so-called “Spring” update via Windows Update, my sources said. If that is the case, Windows 8.1 Update 1 should be pushed to users on April 8, rather than March 11.
A build of Windows 8.1 update 1 has already been leaked on web and we have seen the screenshots as well. If you want to know what all this update will bring with itself, click here. You can also watch the video demo of the leaked Windows 8.1 update 1 below.