Inline conditionals can be a blessing and a curse. In this case, it is absoluteley alright to use them (I find it also more elegant). But I have also seen things like:

    my_fancy_named_variable = my_array.map{|x| do_processing(x)}.sort_by{|x| x.value} unless some_very_long_conditional_that_breaks_readability

This is not very readable, and I would actually use multiple lines to format a call like this.