I saw this floating around on Facebook and clicked on the link to debunk the "confirmation" of this rumor. To be honest, it looks legit, but Carrie Fisher has been known to be flippant with the press.
She was doing the press rounds for a speech called the "Old Bags Luncheon," but she had to cancel for her hospitalization related to bipolar disorder. Before she backed out, she did an interview with the Palm Beach Illustrated, which was covering the event and she dropped this bomb:
Q: Disney is going to continue the Star Wars saga, producing movies set to hit theaters starting in 2015. Can you confirm whether you'll reprise the role of Princess Leia?
That's pretty cut and dry, but she goes on in the next question to say that Princess Leia's future is in a nursing home:
Q: What do you think Princess Leia is like today?
A: Elderly. She's in an intergalactic old folks' home [laughs].
I just think she would be just like she was before, only slower and less inclined to be up for the big battle.
While this isn't "official" confirmation, it seems plausible. But, as with any rumor, until Lucasfilm or Disney announces it, nothing is official.