There are SEVERAL important PHYSICS advancement here, especially the high-Tc discovery (or else it does not warrant the Nobel Prize). First, it was a discovery of superconductivity in perovskite ceramics, a family of material that was NOT known to be superconducting. Second, it was achived out of a parent material that was INSULATING, unlike other known superconductors at that time that starts off as being metallic. Third, it broke the "35K barrier" that was thought to be the theoretical limit for superconductivity.
That discovery caused the major revolution in physics - the 1987 APS March Meeting in NY was dubbed the Woodstock of physics especially after a similar compound, the YBCO123 broke the LN2 temperature barrier. Since then, condensed matter physics had never been the same, and the area of strongly-correlated system just exploded with such a rich variety of new physical phenomena.
The Akimitsu discovery of MgB2, if it was discovered before the high-Tc superconductors, would surely warrent a Nobel Prize. The major physics here is that MgB2 is now thought to be a conventional superconductor with phonon-mediated pairings, but it has a Tc of >40K, something that phonons were not expected to achieve. This has caused the theorists to literrally go back and try to rewrite the theory of phonons in solids. This material achieves a high Tc without the same mechanism as the high-Tc superconductors and without the same structure and compounds. So there are more new physics here.
Go look in Journal of Applied physics, or any material science journal. There are many of such "new" materials being synthesized. New materials does not ALWAYS mean "new physics". If you believe that he has advanced the body knowledge of physics, PROVE IT!