About $32m dollars of ether were just stolen by hackers. This is after the DAO debacle where $150m was stolen. Last week $7m worth of dashcoin - an ether ICO - were stolen.
I looked at Etherium after missing out on bitcoin. I'm not an expert on blockchain but I'm sure they got that part of it right. However I looked at their self-designed smart contract language and it's a joke - an open invitation to hackers - effectively impossible to verify the security of a contract. These robberies will not stop since this is such a significant part of ether.
Also the ICO madness looks like a classic bubble - particularly when you see the amounts of ether being taken off the table by charlatans like Bancor - http://hackingdistributed.com/2017/06/1 ... is-flawed/
Ether is probably great for some short term gambling but I'm skeptical about it's longterm future. Bitcoin is probably a better bet as a long term hold if you want cryptocurrency exposure.
And I don't think "currency" is a good word for this stuff - they should be considered commodities until they start fullfilling the role of a medium of exchange (for other "real" stuff - not pyramid scheme like the new-flavour coins offered in an ICO).