Intel and IBM said they have discovered a way to replace that material with various metals in parts called the gate, which turns the transistor on and off, and the gate dielectric, an insulating layer, which helps improve transistor performance and retain more energy.
Particularly, the narrower your silicon insulators are, the more current bypasses them. Intel only gave a very scarce detail, saying that “new materials” helped improved performance 20% (I'm assuming power performance), whereas IBM remained tight lipped. Some Intel chips have current leakage ratings as high as 50%, so any improvement is good and will lead to chips that run cooler and can be clocked even higher. Especially with the move to 45nm, Intel needs this boost. AMD's current leakage problem isn't as severe as Intel's, but is still a big concern, especially as their clock speeds begin approaching Intel's faster chips.
There was no mention on whether or not the new materials Intel is using will result in more expensive processors.