I figured this one out. It was actually a lot easier than I thought it would be. Here's the code:
protected void ReorderListISPList_ItemCreated(object sender, AjaxControlToolkit.ReorderListItemEventArgs e)
{
// set the Css style for alternate list items
if ((e.Item.ItemIndex % 2) != 0)
e.Item.CssClass = "Alternate";
// set the Css style for edit rows
if (e.Item.ItemIndex == ReorderListISPList.EditItemIndex)
e.Item.CssClass = "Edit";
}