I also lost 42 Ether from this!!!  What's crazy is that it worked before for a small amount.  I was attempting to send the Ether to Bittrex. 

Before you ask:  Yes, I DID check the address of the website and I DID verify the receiving address before submitting the transaction.  I have sent an email to MyEtherWallet.  The address the funds are sent to show multiple entries, but only a couple withdrawals (very small amounts, which is unusual if this is indeed a hacker's account).  I am actually currently the highest "loser" with 42.05387962 Ether sent here.  I will no longer use this service, and I would recommend that other be very wary, as there was nothing I could have done differently (except refrain from using this specific service) to prevent this hijacking.   

Edit:  Also, this was done on a government computer and I just confirmed that there is no malware on my computer.