The big worry is who the unknown players are. Yifu himself said at the recent Bitcoin '13, there could be wealthy vc's developing their own asics for their own use and if they started in Feb, you wouldn't know for a few months before coming online. So their potential impact is a huge question mark until asics are truly distributed in the wild that could negate their centralisation. In essence a 51% is feasible until enough competition exists.
Yifu himself is selling 10's of thousands, but to whom outside this forum, no one knows!!?
There is a forum thread where someone found out the address where avalon sends all the payments for 10k chips to... its quite a bunch of TH till now...
Well, fortunately the Avalon chips are not particularly efficient or hi-tech, and KNC represents the first of the 2nd gen tech. So when enough 2nd gen stuff comes online it won't be profitable for the 1st gen anymore. Plus it's gonna take a lot longer than people think for those chips to turn into working miners, not to mention just to show up.
I'd be surprised if we saw much impact from them before the first of the year.
In any case, we should all be very glad that we're at all into mining when bitcoin are still able to be mined cheaply and plentifully, before mainstream uptake of bitcoin has happened. Trying to mine four years from now would perhaps be a much riskier endeavor, and we won't be talking about ROI in terms of months. It'll be the more standard years by then, and barrier to entry won't be in the mere thousands but more like tens of thousands like starting any mainstream business.
The days are young yet, and it's a good time to mine. We are neo-49er's, COIN RUSH!
Imagine the poor guy who comes of age 20 years from now, who will look back jealously on this historical epoch and the people able to mine now. When 25 bitcoin will be a fortune. We're like the first employees at microsoft who didn't realize they were soon to all be multi-millionaires. That's how I feel. Bill Gate's secretary was eventually worth $40 million iirc