Martin Evening shows a few ways to make Bridge a front end for Lightroom. This includes using the favourites feature in Bridge and Lightroom's watched folder, and as he concludes:

You can use Bridge as a preview browser to inspect folders before proceeding to import them. This can easily save you lots of time since you won't have to go through the Import Photos dialog to preview the images before you import them. Bridge will offer you a much faster route for browsing the photos beforehand.

I kept thinking this article seemed an admission of defeat. Is there so much wrong with Lightroom's initial comparison and editing that photographers no longer want to turn their backs on the unloved Bridge?