The advantage to case statements is that each element is not mutually exclusive, as you have with a single if/elsif/else structure

So, in pseudocode, you might do something like:

switch (value) {
    case 'needs_slight_cleaning':
        &clean_up_values;
    case 'good value':
        &do_whatever_you_need_to;
        break;
    case 'totally unrelated';
        &do_something_else;
        break;
    default:
        &do_some_default_thing;
}
[download]

Note how there is no 'break' between the first two cases, so something that matches the first case will run '&clean_up_values' and '&do_whatever_you_need_to';

It's not an absolutely necessary control structure, but there are some times when it sure does come in handy. (most times when you have a giant if/elseif/else tree, where you're repeating large blocks of it).

Update: I forgot to answer the questions as they were asked:

What type of new control structures you would like to have in Perl?

I'm fine with the current structures

What would be your consideration for the design of control structures ?

Anything that helps me get my work done

Would that make your task easier?

switch/case statements, for the reason stated above.

Can you mimic them with current version (5.6+)?

Yes. With goto.