The support for environments in PDB is for storing the environment
where a catalog/factset/report came from ... and you can certainly
query on it, but currently with ordinary resource collection you
cannot constrain on environment. There is an open ticket in the Puppet
queue to do this in the future:
https://tickets.puppetlabs.com/browse/PUP-2217
For now though one can use something like puppetdbquery, and certainly
filter on environment.
As far as PE inclusion, inclusion of PDB 2.x is slated for PE 3.4 at
this point in time. I'm not sure when the dates for that release will
be confirmed.
ken.