Microsoft is planning to drop the Windows 8 name ASAP. The next Windows update "Threshold" will most likely be called Windows 9 according to Paul Thurrott, and will be shipped in April 2015. Windows 8 Update 1 which is a service pack type update is still on the roadmap for this year. The Update 1 will be much focused on Windows Phone and Xbox integration where as the "Threshold" update will be released as a new name (Windows 9) and will see the return of the Start menu and the ability to run Metro-style apps on the desktop alongside desktop applications. Modern (Metro UI) will be a major focus area of "Threshold"
We can expects three milestone releases (Beta, Release Candidate, etc.) of "Threshold" before its final release in April 2015.