Well you can use link_to_unless_current, but you won't get class="selected". Instead you'll have to code your CSS based on the existence of a link or not.
Right well, in that case you need to do something more robust anyway because you'll want the tab to be an active link when you are on any of the subpages.
However, you can create a helper that will emulate link_to_unless_current with your own semantics so your template doesn't get bloated.