The B&W preview support (B key) has been enhanced starting from build 295:
- A visual B&W indicator has been added to make it clear that the image is currently in B&W preview mode.
- The SaveAs... feature (Ctrl+S) now converts to B&W when saving to JPEG, TIFF, HD-Photo, BMP, PNG and GIF for an image where B&W preview is active.
- The Downscale and Export to JPEG action in the File Utilities batch processor (Ctrl+F) can now optionally honor the B&W preview flag and is able to create B&W thumbnails and web-ready images.
- The Convert Format action in the File Utilities batch processor can now optionally honor the B&W preview flag and is able to convert to B&W JPEG, TIFF, HD-Photo, BMP, PNG and GIF.
- The B&W Preview flag can be set/cleared for all images at once from new menu commands and keyboard shortcuts (e.g. Shift+B, Ctrl+Alt+B, see the taskbar's popup menu for all available commands).
- A new B&W Preview flag selection condition has been added to the File Utilities batch processor, allowing to perform selections on this flag (for example to copy, move or export only the files where the B&W flag was set).
- The Views Filter feature (F key) has a new option to filter images on the B&W flag, there is also a new command (Shift+Ctrl+B) that will set the B&W Flag to all images matching the current filter.
It should be noted that FastPictureViewer's B&W conversion uses a very good luminance-preserving transformation that creates natural-looking B&W images, where the overall brightness and the ratio of dark vs. bright areas as well as highlights and shadow details are preserved, with good overall contrast:

For the time being, it is possible to publish B&W images to the web in two steps: first batch-convert the desired images to B&W using an appropriate batch processing rule in the File Utilities batch file manager, then open the resulting images and publish them to any of the supported destinations.
In the future, the available web-publishing plug-ins (Facebook, Flickr, SmugMug, Zenfolio, PhotoShelter, 500px and the local publisher) will be enhanced to also honor the B&W Preview flag.