The developers of the the highest market share chunk of cryptocurrency camp (Monero) are of the opinion that the maths behind Ethereum is bullshit. I really like the sound of Augur, and it's implication for Ethereum's smartcontracts fulfilled in prediction marketplaces, but with 4 publicly known academic cryptographers incl. a John Hopkins professor saying Ethereum doesn't have the math to back up their claims, I'm not prepared to buy in. On the other hand, Monero, SDK, and the whole money laundering cryptocurreny camp probably is a poor investment at the time of writing given the information I have.
Vitalik says cryptocurrency developers should "reach out to LessWrong more", in order to not be ignorant of advanced computer science and game theory topics.
https://blog.ethereum.org/2014/12/31/silos/
I think Vitalik raises several major important points, namely:
* Bitcoin's $600 million wasted on electricity yearly in order to secure the network is a huge problem. Various Proof of Stake algorithms are attempting to improve upon this. The ideal solution would be one which combines the low cost of the Proof of Stake algorithm, with the high security or Proof of Work. I not enough of an expert to be able to say which solution is best, but both the Ripple consensus algorithm and the Bitshares Delegated Proof of State algorithm look promising. I am interested to see what algorithm Vitalik will choose for Ethereum.
* ASIC miners are a problem due to the resulting centralization. They have also lead to increased centralization in Bitcoin, as the network is now increasingly controlled by a few large mining pools.
* Blockchain technologies have a great potential to change the world, and solve governmental and organizational problems that society is facing. Beyond simply revolutionizing money, blockchain technologies could also be used in the future to support prediction markets, voting/consensus building, exchanges, etc.