From http://xiph.org/ogg/vorbis/doc/v-comment.html:
DATE
    Date the track was recorded
And from http://reference.reactor-core.org/ogg-tagging.html:
DATE
    date or date-time of relevance to the track. The date must be in ISO 8601
format, but may be followed by a space character, then any text you wish,
including the same date in any other format. None of the alternate formats in
ISO 8601 may be used. Only the primary format in ISO 8601 is to be used. q.v.
http://www.cl.cam.ac.uk/~mgk25/iso-time.html eg, DATE="1999-08-16 (recorded)" or
DATE="1999-08-16 recorded August 16, 1999"

So I guess that the date in your file is just crappy. What's the output of
vorbiscomment -l on this file?

$ vorbiscomment -l file.ogg | grep date
date=1969

Does that work fine for you in nautilus ?

If gst-launch gives crap, it's GStreamer's fault :)

I don't think it's GStreamer's fault. 

Whichever module interprets the taglist seems to interpret the GST_TAG_DATE tag
to be the number of a year and not as a date in julian calendar days.

Try this:

#include <glib.h>
int main (int argc, char **argv)
{
        GDate *date;
        gchar  buf[64];
        date = g_date_new_julian (718798);
        g_date_strftime (buf, sizeof(buf), "%Y-%m-%d", date);
        g_print ("%s\n", buf);
        return 0;
}

Result: 1969-01-01

Cheers
 -Tim

Then all plugins except ogg do it wrong... :).

According to gstreamer/gst/gsttag.c, line 93 onwards, yes :P

FWIW, mad/gstid3tag.c and gstspeexenc.c also do it like ogg ;)

AVI, Quicktime, Matroska and a bunch of others don't. Also, Totem doesn't.

Those are all I could find:

2005-03-21  Tim-Philipp Muller  <tim at centricular dot net>

        * ext/lame/gstlame.c: (add_one_tag):
        * gst-libs/gst/riff/riff-read.c: (gst_riff_read_info):
        * gst/asfdemux/gstasfdemux.c:
        (gst_asf_demux_process_ext_content_desc):
        * gst/matroska/matroska-demux.c:
        (gst_matroska_demux_parse_metadata):
          GST_TAG_DATE takes a date in julian calendar days, not a year
          (partially fixes #170306)

Have I missed any or can we reassign this bug to whatever other module needs
fixing? (totem/nautilus/gnome-media/whatever)

Cheers
 -Tim

Let's re-assign to Totem, I need to fix the metadata code.

fixed.