It is the electricity / hash rate ratio that is going to determine profitability. No good having a fast hash rate that guzzles lots of power. Hence ASICS.
Yes, eventually, but right now its the ROI on the initial capital invested that is the key metric. In that sense GPUs and FPGAs are already dead (except for mining with existing kit, and its there that GPUs are hitting the power limit, unless you've got free electric). Unfortunately ASICs are vastly overpriced for their expected ROI, so its not a money making proposition. The prices will have to fall (and its started with the ASICminer usb erupters dropping from 2BTC to 1BTC, though still overpriced IMHO). The manufacturers are laughing all the way to the bank (the usb eruptors have an estimated marginal cost of just $25 to manufacture), at least those that are able to ship product anyway.
, fuck waiting or buying a preorder (super risky IMO). 
