I think 10% to 15% is a very big deal. I'm spending lots of $$ replacing regular incandescent bulbs in my home at the specific request of the power company and the government, in order to reduce the amount of power used, reduce/smooth out peak loads, etc. My actual power savings from doing this might be on the order of 10% to 15%, because lighting is not the main driver of my energy usage. If, after I lay out the capital cost to replace dirt cheap incandescent bulbs with much more expensive LED bulbs (25,000 hour lifetimes, lifetime cost savings, etc.), I find out that these very bulbs are now causing my electric meter to INFLATE my usage by 10% to 15%, I'm going to feel very upset.
The fact that the electric utility forced me to pay for their smart meter upgrade that I didn't want in the first place because it provides me with absolutely no benefit, and in some cases invades my privacy (see work being proudly done at the University of Massachusetts to use smart meter data to determine exact load usage within a home), just rubs salt in the wound.
There seems to be a lot of bullshit flying around with energy policy, and this bullshit leaves consumers getting whacked on both ends - laying out large amounts of capital towards achieving a more "green" environmental impact, then finding out that the cost savings used to justify the capital expenditures were crap because the efficiencies promised were some "best case" scenario, the maintenance cost estimates were lowballed, the expected lifetimes are some policy wonk's fantasy, and now - "smart meters" that are aren't all that smart.
So the headline might be sensationalistic, but if even just the 10% to 15% over-estimates are true, I think it's a big problem. Although lighting isn't my main electric load, there are significant periods of time when it is the only load in my house, and yes, all of my new LED bulbs are on dimmers. Limited selection of light output in LED products has lead to me installing bulbs that are typically over the desired lighting level, which is then reduced through dimmers. And the LED lights tend to be on in more locations than the incandescents were, because they consume so much less power that I thought I could afford to reduce some of the dark corners...