Prior to this, WeMo had a smart light switch, and basically all it did was turn the lights on and off. However with this new dimmable light switch, users will be able to adjust the brightness of their lights depending on their needs. Users will be able to calibrate it for specific bulbs that they are using, and you can even make it so that there are time-specific brightness levels.
This means that if you prefer keeping things low-lit at night, you can set it so that your lights can automatically dim at night, and go full blast during the day/afternoon. It can also be used to help turn your lights on and off on a schedule, which will give the illusion that you are home. Granted it might be a waste of energy, but if it will deter potential burglars, why not?
No word on how much the new WeMo Dimmer will cost, but it is expected to be released later this year.