"Liquidmetal. It's a subtly powerful name, invoking images ranging from self-healing Terminators to Alex Mack. It's also an oxymoron: Liquid, metal. (Note to commenters: Yes, of course, metal can be liquid. Bad word choice.) And while Apple probably isn't getting into the T1000 business, they may have huge plans for our new mystery metal."
Gizmodo goes through a pretty good analysis of what Liquidmetal is, and how Apple might use it. It seems that it has tons of useful applications, and considering it gets stronger in proportion to the force applied to it (or that's my take on it, anyhow), it could be a great replacement for plastic. The video above demonstrates some of its properties.