Yes you can
I'm not sure if you're still looking for a solution to this, but I just figured out a simple solution to create a 2 column drop-down. I haven't tested it yet across all browsers but it seems to be working...
ul#cssmw ul {
width: 250px; /*twice the width of the list item + padding accommodation*/
background-color:#FFF; /*necessary in the case of odd number of list items*/
}
ul#cssmw ul.level-1 > li {
display:inline;
float:left;
width: 120px;
}
ul#cssmw ul.level-1 > li > a, ul#cssmw ul.level-1 > li > a:link {
float:left;
width: 120px;
}