But, a "Data Lake"? Well, it's a diplomatic term, and sounds good for business presentations. But perhaps it's really more like a data junk closet. I've also seen the term "Data Swamp" used. The place were you put all kinds of stuff - and tell yourself that you'll organize it tomorrow. Perhaps.
So which is it..... a sound and wise approach to storing data, or just a dustbin for that which will not be used? That all depends on the organization. Most likely, it will become both, with only discipline minimizing the chaos.
A real purpose
As organizations start to move towards fast data, the data lake will finally take on a true need and purpose. Sensor data, social media feeds, weather data, traffic data feeds, and the list goes on. If it applies to your business, your or your competitor will start to capture it, store it in a data lake, and start to analyze how it impacts your business.
You can find an excellent write up of the uses of a data lake here: http://www.dataversity.net/data-lakes-101-overview/.