Bitcoin mining broke 4 Petahashes/sec, 9 days after 3 Ph/s, 10 days after 2 Ph/s

If you look at any mining profitability calculator, the biggest factor by far is the asymptotic hash rate growth. As difficulty rises, it drives ROI on even the latest and greatest not-yet-released ASICs to essentially $0/month just a couple months after you plug it in, if not weeks.

For example, in the last 90 days difficulty has increased 1150%. Butterfly Labs next-gen - supposedly coming in February - 600GH/sec miner for a mere $5k, will be worthless before it even ships at this rate.

The hash rate growth is so radical, it almost makes you think someone's broken SHA256... Or maybe Butterfly Labs can actually produce those 600GH/sec miners for closer to $100 each, then you have a chance of being profitable when the only real cost is the $30/mo in electricity.

Personally, I think the time has come to switch the proof-of-work algorithm to something that correlates more closely to the original vision of 'one CPU one vote'. The raw hash rate is not nearly as important as the concept of mining being democratized and decentralized.

For example, if there was way to do proof-of-work via proof of committed network bandwidth, storage IOPS, lowest latency transaction forwarding, etc. those are all "real" contributions to the P2P network versus running a essentially a "spinlock".