The Camera Raw plug-in has had a significant overhaul. You no longer have to tie up Photoshop while processing raw files now that the file browser is a separate program. You can select multiple files for raw processing and let them batch process and save in Camera Raw while you return to Photoshop or Adobe Bridge and continue working on other files. You can even add more images to the processing queue while Camera Raw is processing previous files in the background.
Other enhancements in Camera Raw include:
New crop and straighten tools.
Auto adjust check boxes help produce better conversions out of the box.
Preview shadow and highlight clipping.
Set up to four color samplers in each image.
Save custom image settings to an external file.
Copy & paste settings in Adobe Bridge.