They are on a roll today. Another feature pushed live regarding ETC / ETH and sending while preventing replay attacks:
The second most requested featured for MyEtherWallet has only come up in the past 3 days: supporting ETC. We have stated publicly, numerous times, that we will not be supporting ETC. As a free open-source project, we unfortunately do not have unlimited time or resources to build out every feature. We would rather build features that we know will be truly useful to the community in a month and six months and a year for now. We would like to build a foundation for an epic, free, open-source service that benefits all of you.
On a personal level, we did not want to push this feature. We do not support that chain. We do not support what it stands for. And we do not agree with the decision Poloniex made to support ETC, which caused everyone else to follow suit. It is a obvious money grab by a greedy exchange and it gives the attacker funds that should be worthless. It has caused unnecessary confusion, unnecessary stress, and unnecessarily further fractures this once beautiful community.
Unfortunately, not supporting ETC means that regular, well-intentioned ETH holders put themselves in danger due to replay attacks. People need to be able to easily just ETH or just ETC and they should be able to do so without syncing two separate chains on Mist.
So, we have a compromise of sorts. Or a lazy solution. Whatever you want to call it. This enables you to easily send just ETH or just ETC to another place of your choosing (like Kraken where you can promptly dump it or whatever you want). Then you can safely use default transaction once the balance of your account on the ETC chain is 0.
On the send transaction tab you now have 3 choices on how to send ETH:
ETH (Standard Transaction): This generates a default transaction directly from one address to another. It has a default gas of 21000. It is likely that any ETH sent via this method will be replayed onto the ETC chain.
Only ETH: This sends via Vitalik's replay protection contract so that you only send on the ETH chain.
Only ETC: This sends via Vitalik's replay protection contract so that you only send on the ETC chain.
We are NOT displaying ETC balances but we are linking to gastracker.io where you can see the balance of your account in ETC. Keep in mind that gastracker.io is basically where etherchain / etherscan were almost a year ago in term of development. You cannot see gas. You cannot see why a transaction failed. It spazzes out on displaying transactions to and from contracts at times. So be patient and do not rely too heavily on it to verify things, especially transactions to and from contracts.
I love you all, but we want to get back to developing real features (and eating Swiss cheese and chocolates). You can read about our future here.
If you have conceptual questions about how the ETC / ETH chains work, feel free to ask in this thread. I see so much confusion and I, hopefully along with others in this thread, will do my best to educate and help you understand WTF is going on in this crazy multiverse, minus the opinions and rhetoric.
Please do your best to not bother us with ETC feature requests, though. Thank you for understanding and we truly appreciate your support.
In order to send ONLY ETC, you must have .01 ETH in the corresponding address on the ETH chain. This is due to how the contract is set up. My apologies.
link back to OP on reddit: https://www.reddit.com/r/ethereum/comments/4v1y2t/myetherwallet_preventing_replays_and_ethereum/