The greater than 10MH/W is easy. Ztek's current board pushes 190MW using 8.5W so that is ~22MH/W.
I know, its just to make sure they wouldnt sell a GPU based solution, which could easily achieve 1MH/$, but at far higher power consumption obviously.
As far are 1 MH/$. If it gets 50% of their claimed performance it would be $1 per MH for pre-orders and $1.20 per MH for regular orders which would be good but not amazing performance for FPGA.
I would say it is a scam if they don't deliver the performance claimed.
If Butterfly wants to take the bet with the performance as currentlyclaimed, thats their choice, but assuming they havent gotten their software ready and fully optimized yet, think its fair to give them some leeway without labeling it a scam. Remember, half this thread is about fake photo's, non existing business registration what not. If it turns out everything is legit but they miss their performance estimates by 20% or whatever, thats something entirely different as them never shipping a single product and running of with the money never to be heard of again (which is what most here expected).