[рони]

Patron,

var x =[[1,2,3],[[4],[5,[6,7],[8,9]],10]];
function arrMergeRecursive(arr) {
    var temp = [];
    for (var i=0; i<arr.length; i++)  {
        var item = arr[i];
        typeof(item) === "object" ? temp = temp.concat(arrMergeRecursive(item)) : temp.push(item)
    }
  return temp;
}
alert(JSON.stringify(arrMergeRecursive(x)));