[Aetae]

Блджад. *facepalm*

<div id="block" style="background:url(clock.png),-moz-linear-gradient(bottom, #F7E82C 49%, #FFFF47 75%, #FFFF64 88%)"></div>
<script>

function st(prop){
return typeof prop == 'string' ? prop.match(/[^, ].+?(?=, url|, -moz-linear-gradient|$)/g) : prop.join(', ')
}

backgroundImage = document.getElementById("block").style.backgroundImage;

array=st(backgroundImage);

alert(array[0])
alert(array[1])

</script>

Так понятее?

array[0] = "url(image.png)";
array[1] = "linear-gradient(bottom, rgb(76,47,92) 41%, rgb(107,76,120) 71%, rgb(140,107,156) 86%)";