Three Important Developments

Three important developments in Ethereum: Protocol-entangled proof-of-work, move to generic object-model messaging environment and market-based fee structure.

VM-based Proof-of-Work

The oft-tauted "memory hardness" attribute of a proof-of-work (PoW) algorithm is a perhaps sufficient, but not required, attribute in order to guarantee a more-or-less linear investment:payback curve (super-linear curves, where a large investment yields crazy-high returns, as delivered by the first ASICs, are problematic since they concentrate power away from everybody and into the hands of only a few key ASIC investors).

Another way of reducing the "ASIC issue", is to make the algorithm so similar to that of a general-purpose processing unit (a CPU) that implementing as an ASIC becomes pointless.

Ethereum has, as part of the protocol, a defined virtual machine (the EVM). This is the machine that natively executes

Generic Object Model Messaging Environment

Market-based Fee Structure