I've been experimenting with a little bit of an odd workflow, doing most of my inital RAW conversions in Lightroom. When I'm ready to work on images, I load up bridge, and from there open the image in photoshop. I have lightroom set to save sidecar files, and Bridge reads them in just fine.
I open the file in photoshop as a smart layer, in case I want to go back into the RAW converter to make any tweaks, such as density or color. Probably not any better than just using a simple adjustment layer, but seems like it should be.
This works great, but presents a slight challenge when I'm working on a panorama. My normal process there is to work with one of the images, from the RAW conversion all the way through to a test print to try and make sure I feel the RAW conversion is as good as I can get it, before I go through the process of stitching the images, which I do from the RAW files now in CS3.
I've found that if I reopen the smart layer in ACR and make adjustments, the XMP sidecar file isn't updated. Since my goal is to sync the new settings to the other files for the panorama, I'm wondering if there is anyway at all to force an update to the sidecar file if you modify the RAW settings from a smart layer?