All the people claiming power matters aren't showing the math. Power only matters at end-of-life. GPUs are still profitable today. Initial cost and starting date are the biggest factors.
+1 No one's saying it's not more profitable to pay for less electricity, it's just not a deal-breaker for most. Compared to the BFL Single, the bASIC is 90% of the hashrate at 82% of the cost. In the long run, power usage can make up for this discrepancy, but it won't be by much, and hopefully by then both pieces of hardware will have been paid back.