According to this german article, power consumption is the same at idle (1.5W), slightly higher at full single-core-load ( 1.75W vs. 1.6W for the B+), and about 1W higher at full quad core load (2.43W). But keep in mind the new CPU is ~1.5x faster in single task benchmarks, so I'd guess for the same task their power consumption will be equal, or even slightly less for the 2, if you are overclocking your B+.