You're supposed to be able to use control + the pickblock key to copy an item with it's associated NBT data. No matter what I do, I cannot for the life of me get this to work on my machine. I've tried several different mice as well as assigning both 'pick' and 'place' to different letters on the keyboard. I can verify that my control key is functional.
So, after reading some of the stuff referenced in the other bugs, it looks like it's actually COMMAND+pickblock on my machine, not control+pickblock