In Arduino 1.0 it looks like analog pins 6, 7 are supported. There is a "eightanaloginputs" variant defined but all it does is set NUM_ANALOG_INPUTS. NUM_ANALOG_INPUTS only seems to be for users to know if A6 and A7 exist. It is not used in the core.
Here is pins_arduino.h for the "eightanaloginputs" varient:
#define NUM_ANALOG_INPUTS 8
The core code in wiring_analog.c seems to support A6 and A7.
It appears that analogRead may already work on pins A6, A7 for the SMD Uno. analogRead does load the ADC registers with the correct values for A6 and A7 in analogRead.
A6 and A7 can't be used as digital pins since that is not supported on the 32 pin 328 MLF part.