I got it covered (this breaking news story an hour ago). Now that the big exchanges see how much money Poloniex and Kraken are making with multi-coin trading, the big players are starting to take interest.
https://steemit.com/steem/@eatgrits/how-long-before-coinbase-accepts-steem
And its only a matter of time before they go from allowing 2 coins to trade on their platform to allowing the top 10 to trade.
I also touch on why Coinbase acceptance is important.