Does the circuit providing a light at the electrical panel have to be ONLY for that light?
The required lighting outlet for areas with equipment is definitely not required to be on a dedicated circuit. It can be on any general circuit.

Same goes for the receptacle. It is not required to be dedicated, but typically this is. This receptacle is required for unfinished basement areas. It's not required to be at the panel, but usually this is the easiest place to put it.




  2011 NEC
  
  III. Required Outlets
  
  210.70 Lighting Outlets Required
  
  (A) Dwelling Units.
  
  In dwelling units, lighting outlets shall be installed in accordance
  with 210.70(A)(1), (A)(2), and (A)(3).
  
  (3) Storage or Equipment Spaces.
  
  For attics, underfloor spaces, utility rooms, and basements, at least
  one lighting outlet containing a switch or controlled by a wall switch
  shall be installed where these spaces are used for storage or contain
  equipment requiring servicing. At least one point of control shall be
  at the usual point of entry to these spaces. The lighting outlet shall
  be provided at or near the equipment requiring servicing.





  2011 NEC
  
  III. Required Outlets
  
  210.52 Dwelling Unit Receptacle Outlets
  
  (G) Basements, Garages, and Accessory Buildings.
  
  For a one-family dwelling, the following provisions shall apply:
  
  (1)  At least one receptacle outlet, in addition to those for specific equipment, shall be installed in each basement, in each attached
  garage, and in each detached garage or accessory building with
  electric power.
  
  (2)  Where a portion of the basement is finished into one or more habitable rooms, each separate unfinished portion shall have a
  receptacle outlet installed in accordance with this section.