No news on the image processing API front. We're a small team and prioritizing aggressively to meet photographers' expectations. To that end, we are more focused on workflow APIs than image processing APIs. Here are a couple blog posts I've written on the topic:
Can you give me an idea of the image processing plug-in you'd like to create? I know that some of the largest plug-in manufacturers have been willing to accept the external editor compromise for the time being.
Lightroom, Camera Raw, DNG Product Manager
Thanks for the detailed reply Tom and the links to the informative threads As it happens, I'm a developer of image & video-processing plugins for Apple's Final Cut Pro (http://www.lyric.com/fcp-plugins/index.htm) and have been thinking about porting some of the image-processing effects in my kits for general still image & photo work (plus other ideas I have in mind). I realize I can do this via an external editor, not the least of which would be a Photoshop filter port, but I'm a keen Lightroom user and was taken by your use of Lua, so it seemed a more interesting path.
I understand the complexities in supporting non-destructive pipelines & accounting for demosaicing issues, and so on, so it's understandable why it will take some effort to get the SDK right in this area. I wish you well in this endeavour and will continue to watch this space.