It is perhaps an artifact of the bay area but there are many many Tesla vehicles here and many of them seem to use the superchargers for charging[1]. But the question of pollution and CO2 comparisons between ICE vehicles and electric ones, comes down firmly on the side of the electric vehicles (for the case of California at least). The thermal efficiency of converting gas to electricity is over 47% and the closest an ICE can come is about 38%. Lots of additional information from the EIA here [2].

[1] A friend of mine who owns one said the only thing worse than the 20 minute charge time is waiting 20 minutes to plug into an available spot.

[2] http://www.eia.gov/totalenergy/data/annual/pdf/sec17.pdf