Please try out the new Watermarking options in the various output dialogs:
Print Proofs
Save As
Send Photos via email
HTML Export
FTP As
PhotoShelter upload
Let us know how it works for you. Note that on the Mac version, the preview really only is capable of showing the font style, size and opacity. Bold, Italic, and Drop shadow do not always work. I will eventually add a preview for both Mac and Windows that will be fairly accurate.
-Kirk