Digital BW, The Print

Having worked in museum for more than twenty years, I'll jump in and
give a perspective from there...  Dry mounting was very prevalent for
photographs up through the 60's as it provided stability against curl,
physical protection, and even a little extra crispness from the little
bit of ferrotypeing that would occur under the heat and pressure. 
However it began to lose favor in the 70's as photography became more
and more a "fine art".  Traditionally, other print media would be
hinge mounted and art photographers began doing this, in part to
emulate fine art.  And while it was long suspected that dry mounting
was an archival problem in that the fusion material may have
deteriorative effects on the print and mount, over time it became
evident that more often the problem was the deterioration of the mount
board itself.  Photographers also began printing with the image well
within the paper edge, in part to emulate other print types (and
separate them from the 1/4 inch borders of commercial printers) as
well as providing a visual "matt" for the image when showing a box of
prints without the necessity of mounting everything.

The most compelling reason not to use permanent mounting techniques is
that, as the mount/matt is meant to protect the print from physical
damage, it invariably becomes damaged itself and needs to be replace.
 Also, as presentation styles change over time, prints can be
re-matted to fit the current trend.  Having the ability to easily
remove and replace the mount/matt is really a necessity over the the
life (100+ years?) of a print.  Believe me, having had to prepare
prints that were dry mounted for exhibition can be a major pain.

I would recommend mounting prints with archival tape using the "T" or
"hinge" mount technique.  Archival tape will not damage the print and
can easily be removed by dampening from behind.  If you want to
"float" mount a full bleed image, you can to it with a hinge mount. 
It will not lay perfectly flat, but it does give an "artistic" effect.
 Archival photo corner mounts are also acceptable for small prints but
make sure to leave a little extra play in them for expansion.  Of
course, if you go this way, you'd want to sign the print so that it
travels from mount to mount.

John