UPDATE: Pink Floyd have officially announced the album on their website:

Pink Floyd can confirm that they are releasing a new album, The Endless River, in October 2014. It is an album of mainly ambient and instrumental music based on the 1993/4 Division Bell sessions which feature David Gilmour, Nick Mason and Richard Wright. The album is produced by David Gilmour with Phil Manzanera, Youth and recording engineer Andy Jackson. Work is still in progress, but more details to come at the end of the summer.

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Bet you never thought this would happen: Pink Floyd will be releasing a new album in the fall to coincide with the twentieth anniversary and deluxe reissue of their final album, The Division Bell. The new album is called The Endless River and is based on 1994 sessions with Richard Wright. As CoS points out, the news was revealed on Twitter by David Gilmour’s wife Polly Samson, who calls it “Rick Wright’s swansong and very beautiful.”

Btw Pink Floyd album out in October is called "The Endless River". Based on 1994 sessions is Rick Wright's swansong and very beautiful.

— Polly Samson (@PollySamson) July 5, 2014

Durga McBroom Hudson, a live backing vocalist for the band, shared some more details on her Facebook page, including the photo above: “The recording did start during The Division Bell sessions (and yes, it was the side project originally titled “The Big Spliff” that Nick Mason spoke about). Which is why there are Richard Wright tracks on it. But David and Nick have gone in and done a lot more since then. It was originally to be a completely instrumental recording, but I came in last December and sang on a few tracks. David then expanded on my backing vocals and has done a lead on at least one of them. That’s the song you see being worked on in the photo.”

The Endless River will be out in October.