I view it more as an novel solution. The Pi's power cable is Micro-USB, so buying things that interact with that standard rather than hacking up your own cables makes a bit of sense.

That hub is $50 USD: http://www.amazon.com/Plugable-Power-Adapter-VL812-Chipset/d...

So it works out to around $7 for each Pi, probably closer to $10/each with cabling, which is quite reasonable for a slickly put together setup.

That hub also has a 4A power supply, which is probably needed for a few heavily loaded Pi's.