Err... what yagan said
This is no small accomplishment indeed.
I guess I'll have to tell what is happening with Sibley
I'll have a more detailed blog entry about this ready in hopefully one or two days, but Sibley has officially requested that IMSLP mirror all of the contents of the Sibley online collection. They have also received a very substantial grant to scan more scores, and these will be mirrored on IMSLP as well. Please thank jfarrington above who is the Sibley librarian