Surprised there doesn't appear to be any posts on here about it.
If you don't know what it is, I suggest you give yourself an hour or two of time and get your google fu going.
It's basically Bitcoin redux, but using the blockchain to implement smart contracts, rather than just a currency exchange and hold protocol like Bitcoin is.
Bitcoin is making headlines for increasing 2.5-3x in value this year... Ethereum has increased 26x this year in value - and today marks a big day with large Chinese exchanges starting to sell it.
Yesterday is passed Bitcoin in market capitalisation, with a lot of pundits saying it's pretty much going to overtake bitcoin in the near future - mosty down to Bitcoin self imploding with in fighting about what to do with its inherent problems (Which Etheruem has more or less solved).
Interesting times ahead!