Hi,
No automatic method on the upload. You can select multiple images in Image Management. One method to work in the existing system would be to upload to a specific Folder, bulk watermark those in the Folder, and then move them to respective completed Folder(s).
I do think a more comprehesive methodology on watermarking is a good idea with image (not just text), rotation, placement, size, color, opacity preference settings for a faster processing and more flexibility. Maybe a special WATERMARK upload folder that ties the upload to automatic post-processing to add the watermark with your default preferences. Tieing method to folder isn't new for them. They do it with listing imports. Methods on objects....there's a concept....hehe.
This is a great discussion item. Maybe one to add your comments to at the new "Feature Center" at the Home tab.
Danno