
From Garrett:
Basically you set the img src to be the 1x image then you give it an id="asdk-logo"and stick this in your CSS
only screen and (min--moz-device-pixel-ratio: 1.5),
only screen and (-o-device-pixel-ratio: 3/2),
only screen and (min-device-pixel-ratio: 1.5) {
#asdk-logo
{
content: url(/img/logo@2x.png);
}
}