Martyn + Four Tet - Glassbeadgames (8 Hours at Fabric Dub)
There's little info about this tune from Martyn and Four Tet, but you've probably heard it in one of their DJ sets from the last couple of months. Apparently, it's taken from Martyn's forthcoming album The Air Between Words on Ninja Tune, set for a release in mid-June. Judging from the name, the version you can hear above is probably different from the album track. As I said, no info available.
May 6, 2014 Kieran just confirmed on his new show on NTS Live, that the version above is not the one on the album. Instead it will be available on a separate 12-inch.