[demallien]

Memory bus bandwidth - moving large chunks of data around just got twice as fast. That means loading textures for games, or hauling photos up from flash memory will be substantially faster now.

[kllrnohj]

Memory bus bandwidth has nothing whatsoever to do with CPU word size. You'll have to wait for LPDDR4 for an increase in memory bandwidth.

[mikeash]

There's no mandatory relationship between word size and memory bus size. 128-bit memory busses were common well before 64-bit CPUs were.