The new and improved wire labels in LV2010 are neat, but could be even better if they did not loose their labels when wired into or through structures and/or sub-VIs:
My suggestion is that a wire, when labeled, should keep the label name when the wire value is not changed or able to be changed. Even through structures and sub-VIs, like most PCB routing programs with their "signal names".
It would also be reasonable that the wire label value should default to the name of the control where it is originating.
In this way, using the wiring-tool, you will get much more readablitity in your diagram when debugging code. A right click option of "highlight signal wire" could be the next step ;o)