I'm working on another book project that involves editing a lot of photos in Lightroom and importing them into InDesign. There are lots of cycles of importing into InDesign, looking at the images, deciding on an edit, making the edit in Lightroom (brightness, contrast, etc.), reimporting into InDesign, etc. It would be really cool if you could export a photo from Lightroom as a Smart Object into InDesign. You can export as a smart object into Photoshop. Why not InDesign?
After playing around more, it looks like the Smart Object communication between Lightroom, Bridge, and Photoshop doesn't exactly work the way I was expecting. I've got some learning to do here but I think this could be really cool.