When "The Division Bell" was released back at 1994, the idea was release a double record, one of them just with instrumental music, as for that record they jammed a lot together and recorded many ideas for songs. The project of the double record was abandoned and the songs were filed.
Before Rick Wright died in 2008, they (David Gilmour, Nick Mason and Rick Wright) talked about it and the idea of revisite that songs was a kind of promise to Rick by David and Nick, so they started to listen to the many hours of music recorded and trying to figure out what pieces make sense to built songs. It took time, but they found it, and started to re-record almost everything except, obviously, Rick Wright´s keyboards parts.
The critics are being quite hard to this last record, that has to be understood as a homage to Rick Wright, and to the Pink Floyd´s legacy. There are references to many of the Pink Floyd catalogue in all this songs, pieces that reminds you to some Wall´s sounds, to Shine On You Crazy Diamonds, to Animals,even to songs from the very early years of the band, being Rick Wright always the main focus of it.
Of course it's not a record that follows the Pink Floyd standards, even the David/Rick/Nick trio encarnation, which was weaker in comparation with the last records with Roger Waters (exception made with The Final Cut, which was a Waters solo record with David and Nick playing around, and realesed under the Floyd name), but this is not really a new record of a living band, it's the Swan Song of one of the greatest bands ever, closed with "Louder Than Words", the only song with lyrics, that talks about the Pink Floyd History, and closes it forever.
