sadzeburo, достаточно синхронно?
<!DOCTYPE html>
<html>
<head>
<script src="http://code.jquery.com/jquery-latest.js"></script>
<!--
<link rel="stylesheet" type="text/css" href="tmp.css" />
-->
<style type="text/css">
</style>
<script type="text/javascript">
$(document).ready(function (){
$('option[value="1"]').attr('selected',true)
})
</script>
</head>
<body>
<form>
<select name="en[]" multiple='multiple'>
<option value="1">Kiev</option>
<option value="2">Kharkov</option>
</select>
<select name="ru[]" multiple='multiple'>
<option value="1">Киев</option>
<option value="2">Харьков</option>
</select>
</form>
</body>
</html>