It's a marketing Gimmick.
The wattage ouput of an LED has nothing to do with the output that it makes, unless those LEDs are being driven at recommended rates. Take for instance a Luxeon I LED QYAH (~3.3V @350mA) and a Luxeon 3 TXOJ driven at the same values as the Luxeon I. They will both be putting out about 30 lumens, but the Luxeon III is more efficient. Take for instance the Mini Maglite LED. The 2AA version states that it uses a Luxeon III but, it is only be driven at 1 watt, thus making it efficient, but not as bright as it should be. Luxeon III white LEDs normally get driven around 700-1000mA. If your friend has a luxeon 3 with the stated bin that I have listed and it is running around ~3.3v at ~700mA then it will be brighter in over all output and not necessarily throw ouput. You have to realize even if a lower wattage LED seems brighter in a distance (throw) test, it's over all output may be lower. Take for instance the 3 watt LED and give it a TIR (collimator) lens and the Luxeon I the Reflector. The luxeon I will have a higher Lux reading for the throw beam, but the over all will be lower than the Lux III. The lux III in this scenario wilil have a higher over all output and a lower throw output.
Also, your eyes can mislead you, I have a Luxeon I light that seems brighter than a Luxeon III light, but according to both the over all and throw lux readings the luxeon III light is actually brighter even though the Luxeon I light SEEMS brighter.
Basically, wattage is a way to hoax the every day person into buying a light, but if you look closer, a lumen rating trells you much more about the light. A high quality one watt light that is rated at 45 lumens output could actually be putting out more light than a no name brand 3 Watt LED light. So be careful what you buy.