Ironically, provenance metadata on the data field level (i.e., for every data field) has become available just now in MARC:

From: Simon Spero
Sent: Thursday, May 9, 2013 19:32 PM
Reply To: Bibliographic Framework Transition Initiative Forum
Subject: [BIBFRAME] Provenance

On Thu, May 9, 2013 at 2:05 PM, Charles Pennell <[log in to unmask]> wrote:
I'm rather fascinated by the idea of establishing provenance at the element level, and certainly for far more elements than the 4-5 fields defined as non-library contributed metadata in this discussion (summary, TOC, sample text, biographical info, and publisher description).