With the new plugins-functionality you could create your own special sorter that uses data attributes too. Then you would call it with listObj.yourSortersName(something).
And you can still use the regular sort function which since this version is a included in the helper object :)
Actually I realized I can already do this even without plugin functionality. The Item object passed to the sorter has access to the element http://screencast.com/t/Z5uVYNtH8