The hot new (3/2/01) superconductor.
This rather simple compount exhibits superconducting properties at 39 Kelvin which, compared to the recent ceramic superconductors that work at ~150 K, doesn't sound like much. The big difference is, MgBr2 is thought to work like the older metallic superconductors. Additionally, it has physical properties that may make it more amenable to making wires out of it.
This discovery was published in the science journal _Nature_, by JUN NAGAMATSU, NORIMASA NAKAGAWA, TAKAHIRO MURANAKA, YUJI ZENITANI, JUN AKIMITSU
Is this the beginning of practical superconductance that will change the world? All we need is fusion and superconductors, and we'll have the Star Trek Utopia, real soon now.