I have changed my diff machinery to use version-completion tables.  

I have resolved Dan Nicolaescu's two buglet reports, deferring one
to post-merge.

There are no other known merge-blocking issues with new VC.

The -ub diff is down to 1313 lines.  I think that's as small as it's 
going to get.

Here is substantively what the changelog entry will look like,
following RMS's directions.  If I have the format wrong, someone
please correct me.

* vc.el (vc-next-action): Completely rewritten; this principal entry point now 
  operates on a current fileset selected either explicitly via VC-Dired or
  implicitly by visiting a file buffer, rather than always operating on the 
  file of the current buffer as in older versions.  The rest of the mode
  has been rewritten to match.
  (with-vc-properties): Rewritten to operate on a file list.
  (with-vc-file): vc-checkin takes a file list argument now.
  (vc-post-command-functions):  This hook now receives a file list. 
  (vc-do-command): Now takes a either a file or a file list as argument.
  (vc-deduce-fileset): New function for deducing a file list to operate on.
  (vc-next-action-on-file): This function is gone, it is merged into
  vc-next-action.
  (vc-next-action-dired): This function is gone, it is merged into
  vc-next-action.
  (vc-register): Adapted to the fact that vc-start-entry now takes a file list.
  (vc-register-with): New function.
  (vc-start-entry): Now takes a file list argument rather than a file argument.
  (vc-checkout): Modified to cope with vc-start-entry taking a file list.
  (vc-steal-lock): Modified to cope with with-vc-properties taking a file list.
  (vc-checkin): Now takes a file list argument rather than a file argument.
  (vc-finish-logentry): Use the filelist passed by vc-start-entry.
  (vc-diff-internal): Completely rewritten for filesets.
  (vc-diff-sentinel): New function, tests whether changes were written
  into a diff buffer.
  (vc-diff): Completely rewritten for filesets.
  (vc-version-diff): Completely rewritten for filesets.
  (vc-print-log): Now takes a fileset argument.
  (vc-revert): Now reverts the entire selected fileset, not just the
  current buffer.
  (vc-rollback): Now rolls back the entire selected fileset, if possible.
  No longer accepts a prefix argument.
  (vc-update): Now merges new changes for the entire selected fileset,
  not just the current buffer.
  (vc-revert-file): Modified to cope with with-vc-properties taking a file list.
  (vc-default-dired-state-info): Add + status suffix if the file is modified.
  (vc-annotate-warp-version): Use the new diff machinery.
  (vc-log-edit): Now takes a file list argument rather than a file argument.

If nobody raises either a new merge issue nor a new bug, new vc.el is ready
to go in.  Full copy is enclosed.

Dan, I'd appreciate getting a green light from you within the next
couple of days.  I want to get to work on the post-merge issues
(including your "No fileset is available" gripelet, speeding up
VC-Dired, and the terminology cleanup) but right now I don't want to
do anything that will cause new VC to diverge more from CVS head.
-- 
		<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>