Standard incandescent bulbs produce light & heat.
LED bulbs produce mostly light and very little heat.
The difference in heat produced can affect the cost effectiveness of LED bulbs in colder climates.
In other words, the heat added to your home by incandescent bulbs is heat that your furnace does not have to produce. So running incandescent bulbs directly offsets the amount of energy your furnace has to produce. Incandescent bulbs are 100% efficient at turning electricity into light and heat.
Now over a 10 year period, your incandescent bulbs will cost those of you living in cold climates about $2 for five 1500 hour bulbs. A CREE LED bulb will be about $10 over the same 10 years (their gaurentee period).
This cost difference can be quite large if your home has many light bulbs. Say your home has 25 bulbs: this would be $50 vs $250.
There is another confounding factor in heating your home vs light bulbs: Does your heating system cost less to operate than an electrical heating system?
If you have electrical heat, all the aforementioned information is exactly accurate. However, if your home is heated with some other form of energy, which is cheaper than electricity, the value of the heat produced by incandescent bulbs may be reduced.
When you run your air conditioner the air conditioner has to work to pump the heat produced by the incandescent bulb out of the house. This extra work costs money. The LED bulb produces less heat and thus less work for the air conditioner. You save money powering the LED bulb and you save money because of the low heat output of the LED bulb.
This banning of incandescent bulbs is an excellent example, by the way, of why governments are bad at regulation. Governments tend to create one size fits all regulations, which really do not fit all. And they remove from the citizen the freedom to individually make the most cost effective choice.