New technology lets compact fluorescent lamps dim as far as incandescent bulbs.

Compact Flourescent Lightbulbs are generally on or off.  There is very little dimming that can be done just because of the nature of the CFL bulb.  This is starting to change with a new series of bulbs coming out which have electronics in them to allow for true dimming bewteen 1 and 100% brightness.  They are to be available later in 2010 for a yet to be determined cost- probably not inexpensive.  Over time the price should come down.