As a result of a Google Summer of Code project, PAlex has been working tirelessly to develop a library which will be incorporated into the core of Joomla! hopefully from 3.2 onwards. The concept is quite simple - a centralised library which extensions can call upon to retrieve the correctly formatted microdata for their information.
The microdata library has been through several iterations to ensure that it is flexible, fast, light, and intuitive to use for developers. It also needs to support potential changes in schema going forward, should search engines switch their preference from schema.org to other data vocabulary sets.
If you want to take a closer look, you can find the library here: libraries/joomla/microdata
If you'd like further information about how it all works, check out this Gist: https://gist.github.com/PAlexcom/6339949
How will this effect Microdata for Joomla
We'll still be providing our services, however we will be re-writing all of our overrides for 3.2.x and beyond to use JMicrodata (assuming of course that the developers have not already incorporated this into their extensions).
We will be back-porting our template overrides to cover the Joomla! 2.5.x and 1.5.x template overrides for core Joomla! and popular extensions which continue to support earlier versions of Joomla!, in addition to our pre-3.2.x overrides.
Of course, we'll still be championining Microdata whenever we get the chance and keeping up to date with all the latest developments!