I believe RenderMonkey may have the sort of functionality you are looking for, it just isn’t easily accessible in the beta that has been released so far. RenderMonkey is a simple shader development tool like you can presently see, but it is also a plugin frame work. Virtually the entire tool is built on the plugin frame work, and it allows for additional plugins for exporting from its internal data format.
The plugin system is not documented in the initial beta, but it is scheduled to be included in the next release. The idea of the plugins is to allow developers to adapt it to their own uses. As far as D3D versus OGL, the previewer itself is a plugin.
I’ll forward this threasd along to one of the team members to see if they can comment further.
-Evan