GeoServer always tries to stay up on the latest standards, but up until recently, no one had funded WMS 1.3. Most of the needed infrastructure was already in place, as it was required for WFS 1.1, but the bindings needed to be built and it needed to pass the CITE compliance tests.
A nice addition would be to also implement Symbology Encoding 1.1, the successor to SLD, as it is more in line with WMS 1.3. This has been partially implemented at the time of writing.
Funding
This roadmap item was funded by Ordnance Survey. Thank you!
WMS 1.3 was first added to GeoServer in the 2.1-beta3 release, and will be a part of version 2.1.0 when it is released. WMS 1.3 was added to the OpenGeo Suite Community Edition 2.3.2 and will be added to the subsequent OpenGeo Suite Enterprise Edition 2.4.0.
Other Roadmap Items
Funded: A new, cleaner user interface built on the Wicket web framework debuted with GeoServer 2.0
Integrated Web Processing Service (WPS)
Funded: A WPS in GeoServer will be integrated into GeoServer 2.1 to perform real operations at the level of the data instead of relying on parsing GML or reading large raster files over the network like the standalone WPS implementations.
Currently features are only accessible via the Web Feature Service (WFS) API. REST feature access will provide a ”resource oriented“ approach to accessing geographic collections. It will also use the existing AtomPub specification to provide for feature viewing and editing.