From the information available on the US Department of Energy website, I’ve put together this graph showing the implementation of new efficiency standards for incandescent light bulbs. The standards that went into effect on January 1st, 2012 only affect 100W bulbs. Now bulbs in the range of ~1500 – 3600 lumens (the unit of light) must be 72W or less. The same will be true of 60W bulbs on 1/1/13, decreasing to an upper limit of at most 53W, and 40W bulbs on 1/1/14, decreasing to an upper limit of at most 29W.
Specialty light bulbs, as defined by the law implementing these lighting standards, are unaffected by this law.
The reason for these standards was a lack of technology turnover in the area of lighting. Incandescent light bulbs barely changed in efficiency for about a century. Other technologies did exist previous to these new lighting standards, but the dirt cheap incandescents made market penetration of new lighting technology almost impossible. State lighting laws preceding these federal rules, spurring technology changes and market penetration. These new standards have barely come into law on the federal level, and they already have induced additional focus and innovation in the area of lighting. In essence, these standards will form a lid on lighting energy usage, helping to decrease demand for energy while keeping the same lighting service quality (in lumens).