A friend and I stumbled on to this last night. I've never heard about this effect before and thought it was interesting.
From the PDF:
While Gschneidner and Pecharsky’s prototype was a landmark event in
the field of magnetic refrigeration, it would likely remain nothing more than a
curiosity were it not for the fact that the team’s device is more energy efficient
and environmentally friendly than virtually any conventional refrigerator on
the market today. Because the relatively inexpensive permanent magnet
handles the cooling without the need for additional energy input, electricity
is only needed to turn the wheel and circulate the streams of water. For its
part, water, even when combined with an environmentally friendly antifreeze, is
more benign than the chemical coolants presently in use.
Gschneidner was instrumental in development of refrigerators that
harnessed this phenomenon in place of traditional gas-compression-driven
cooling.
"The biggest stumbling block we now face is coming up with a GMCE
material that doesn't progressively break down into smaller pieces over
the billions of magnetization/demagnetization cycles required for a
15-20-year appliance life," he says. "We also need to reduce the time
dependence of the transformation."
Based on the current pace of research and the growing number of working
prototypes around the world, Gschneidner expects magnetic refrigeration
to become commercially viable by 2016 or so, a fruition he plans to
witness.