This is indeed great news. I was about to post it but saw you beat me to the punch.
But yeah, Daredevil, Luke Cage, Iron Fist, and Jessica Jones series all coming from Netflix, leading up to a Defenders mini-series.
I totally called the Daredevil series thing...as I said the character will work much better in a series format as opposed to a movie (or even movie trilogy), as it allows his world to be better expanded and also the legal drama aspect to the character to get more focus than a film would allow.
Luke Cage, Iron Fist, and Jessica Jones all seem tailor made for series as well.
And The Defenders? Yes please! It's interesting that the article mentions reimagining the Defenders...I assume that means this version of the Defenders will consist of Daredevil, Cage, Iron Fist, and Jessica Jones...which essentially makes it more of a Marvel Knights inspired team, as I doubt we'll see Hulk, Dr. Strange, Namor (definitely not Namor since I think Universal still holds the rights to that character), Silver Surfer (and Fox owns the rights to him).
It also remains to be seen if it will in fact be a part of the MCU. I'm sure it will be (that'd be the smart approach, since it's built in advertising and hype for the hugely successful MCU series and act as a Television extension of Agents of SHIELD), but you never know. The fact it's airing on Netflix might have come with some exclusivity deal requiring it to be its own thing...but I doubt that, as Netflix stands to benefit greatly by tying it into the existing MCU.
Exciting either way.
I'm going to hold off adding it to the timeline until it's confirmed it's an MCU property and it does indeed happen (basically once filming starts...there's always the possibility--however small given the success of the MCU--that it could fall apart before filming commences).
However, given the fact they're aiming for a 2015 premiere, I think its a safe bet they'll be trying to cross-promote it with Avengers - Age of Ultron and Ant-Man.
And who knows? Perhaps The Defenders (assuming it is a part of the MCU) will spin off into a film as part of Phase 3...or even Phase 4.