Mary Jo Foley has an article running which almost confirms a few of the rumours:
Windows Blue named Windows 8.1.
Blue to be free.
Available through the Store and not Windows update.
Initial public preview release end of June 2013.
Release to manufacturing around August 2013.
Includes GUI optional changes to include Start Orb and boot to desktop.
You can read the full article here:
Microsoft confirms Blue to be free for existing Windows 8 users | ZDNet
Windows Blue named Windows 8.1.
Blue to be free.
Available through the Store and not Windows update.
Initial public preview release end of June 2013.
Release to manufacturing around August 2013.
Includes GUI optional changes to include Start Orb and boot to desktop.
You can read the full article here:
Microsoft confirms Blue to be free for existing Windows 8 users | ZDNet