A blog detailing a little more about Windows Blue has been posted by Microsoft:
The inclusion of a new Start icon is mentioned along with details concerning:
Personalisation,
A better search function,
Improved keyboard and mouse options,
Internet Explore 11,
Cloud Connectivity,
Apps and...
apps
cloud connectivity
enhancements
improvements
internet explorer 11
keyboard options
microsoft
mouse options
pc settings
personalisation
search function
start icon
storeimprovements
windows 8.1
windows blue