In 2.10.xx the 'hippo' namespace is http://www.onehippo.org/jcr/hippo/nt/2.0.1.  

It is upgraded from version 2.0 to version 2.0.1.

 

CND files with the 2.0 version number are still accepted, XML files where the JCR namespace
is declared as an XML namespace are not, so if you did not remove the XML declarations from your content and configuration XML files, you have to upgrade or remove them now.

 

The updater modules are relevant when you have created your own plugin, with it's own node types.