Geoserver (http://docs.codehaus.org/display/GEOS/Home) will hopefully add another service to it’s 2.0 release. The FROGS (http://frogs.tigris.org/) project has implemented a WPS, and is likely to join forces with geoserver. According to OGC “A WPS may offer calculations as simple as subtracting one set of spatially referenced numbers from another (e.g., determining the difference in influenza cases between two different seasons), or as complicated as a global climate change model. The data required by the WPS can be delivered across a network, or available at the server”. cool huh :)