Haven't heard of it yet? You will. It's an opportunistic pathogen that is extremely resistant to antibiotics—some people call it a super bacterium. Jon Carroll writes about it in his column today, which, like all of his columns, is a great read.
Jia-Rui Chong's article in the LA Times fills in with more details.
I have a hard time panicking about bird flu, but I find Acinetobacter baumannii scary.