The 'Threshhold updates' are a collection of updates for windows 8.1. Some are saying that this is windows 8.2 but see for yourself:
Reference:
http://winsupersite.com/windows-8/further-changes-coming-windows-threshold
consolidated os
consumer focused
enterprise sku
floating windows
metro ui
microsoft plans
modernmix
next version
pc users
product versions
release information
skumorphing
start menu
threshold
update
user experience
windows 8.1
windows phone
windows rt
xbox one
