The State and Future of JavaScript [Video]

http://developer.yahoo.com/yui/theat...conf2009-state

It's quite interesting. I had never heard about the problem with IEEE-754 in ECMAScript/JavaScript that he talked about.
JavaScript Code:
var x = 0.1;
var y = 0.2;
var z = x + y;
alert ('0.1 + 0.2 = ' + z);
if (z == 0.3) {
    alert("0.1 + 0.2 == 0.3");
} else {
    alert("0.1 + 0.2 != 0.3");
}