If SHA2 were broken the breaker could mint coins at a faster rate than brute force.  How much faster depends, could be tens or hundreds of times faster..  If the breaker is intelligent, he/she could slowly cash in over a period of a few years, walk away with a pile of cash and a world full of inflated Bitcoins.  This would be an opportunity to cash in on research without the guilt of doing anything illegal or immoral.  Don't look for them to publish a paper in ASIACRYPT14.

Another point, when a break is found it is usually followed by a improved break in a few months or so. 

Just remember that the road of the past few decades is littered with broken hashes: MD4, MD5, SHA0, SHA1 and many others.

There are two big obstacles to widespread use:

1. Trust as it applies to online transactions.

2. Speed as it applies to small face-to-face retail transactions.

If there is ever enough financial incentive for a few large trusted online retailers like Amazon to accept Bitcoins the first obstacle could be overcome.   Reloadable smart cards would encourage face-to-face retail transactions if they can be completed in much less than a minute.  Of course people would have to understand:  lose your card, lose your money; just like hard cash. 

The big advantage is anonymity. GPS, cameras everywhere, credit card trails; Big Brother isn't coming, he is here.  Of course most people don't care until they are the target and then it is too late. 

MOST people don't.  MOST people are short term.  

I have a belief in reincarnation.  Not a very strong belief but there is some scientific evidence.  I don't really care about the fate of Bitcoins in 2140.  I do care if there is a civilization that even remembers the meaning of Liberty in 2140 but there isn't much I can do about it.

BFL appears to be severely mismanaged; that might qualify them for some Stimulus money. 

If I run it in the winter I can eliminate one of my 1500 watt space heaters so the power won't cost anything.  Heating season is only about two months here (New Mexico high desert).  Not planning on making a living with this stuff anyway.

Last time I looked they do NOT publish power consumption.  KWH per bitcoin or KWH per GHS will tell you what their product is worth. 

You may be right, but it is what I got with no investment.  I am not planning on making a living with this.

I am planning on using a water cooled setup that I used for research a few years ago.  Four 9800GX2 Nvidia cards (8 GPUs), two quad core Opterons, two pumps, three radiators, three fans, large modified Lian Li case.  I can run it in the winter for free!  It will replace one of the 1500 watt heaters in my home that usually runs 24/7 in the cold months; same BTU's.  It will probably be winter by the time I get it all set up.  Long term, maybe some government subsidize solar panels if they have any programs going next year; a lot depends on the Bitcoin/KWH exchange rate.

No, but I've always wanted to see it.  Living on the Mediterranean and on the Front Line of Western Civilization at the same time; quite a combination.

Let's assume technical advances in speed and security.  BC usage would gradually expand.  At some point in this expansion of usage governments will see a clear threat to their sales taxes, income taxes and VATs.  It is not clear how but they will try to co-opt the system is their revenue stream is threatened.  They might even try to launch a competing digital cash system with the government as the trusted arbitrator. 

Hi, I am taking a very preliminary look at bitcoin mining.  I have a linux box with four 9800gx2 GPUs that might be suitable.  I would need a big UPS or live with half a dozen power failures which will occur this summer.  With current software, what are the potential losses for operating without a UPS?  Recoverable graceful failure or catastrophic losses?