It is wrong impression that FPGA consume more power. It all depends what you are comparing with. If you try to implement the some FPGA features into software running ARM or similar processors, you will use 10x if not 100x more power.
I first heard about this concept at FPT in Beijing last year. It sounds good, but I will wait and see how it is implemented and what the overall cost is. It will probably fly for some high performance apps where cost is not an issue, but let's see how far down the cost curve this idea goes before making a final judgment.
There are plenty of applications for this basic concept of FPGA cross over for SoC. However, we have not seen any practical implementation. One urgent requirement is SoC with FPGA for video processing of CMOS image sensor with HDMI output. Can Xilinx take lead and provide some demonstration for this? This may be again suited for medium volume application. For high volume application, it may not be cost effective.