The old copy menu script got some love lately, works fine in beta 2.54, solves some bugs, gets pep8 compliant and its own wiki page:
It has a few options not available from the buttons (e.g. copying pose bone visual transforms) and provides the comforts of 2.4ish interaction 
Quick edit: the script is now in trunk and contains edit mode functionality, updated the url accordingly…
Awesomeness!
One of the things I missed so badly in 2.5
Thanks Baba!
See you in Amsterdam!
Seb
It’s Nana, damnit! see you in A’dam
Not only the script is good, the wiki explanation is quite thorough. Thanks for
both!