I bet a dollar it is on a single outlet because it is in a basement. The original electrician installed a single recp. to avoid putting in a GFCI.
If you replaced the single recp. with two duplexes and I am in fact correct in my assumptions, then you would have to protect this circuit with a GFCI.
Interestingly enough, In 2008 NEC the rules change for basements and garages, with the elemination of the exception for single recps on normally protected circuits. Now how big a nerd am I for already having my '08 codebook when GA won't adopt until '09??