It will be nice to see vendors implement the NVMe connectors in the desktop mobo's, which in turn will redefine case design, as less storage space will be required for storage. I am aware that the initial intent is to direct these at the mobile market, but desktops can benefit as well.
You'll really see NVMe take off on the desktop with the move towards SATA Express. A SSD on SATA Express will leverage NVMe and two PCIe Gen 3 lanes. Though some motherboards will (and already do) have M.2 connectors, M.2 really makes more sense in mobile applications. M.2 will only get traction on the desktop insofar as it will begin to replace mSATA. Tons of mainboards, especially smaller form factor products embrace mSATA, and moving to M.2 is a natural transition. However, M.2 drives are hard to find right now, and we really won't see a plethora of options until next year.
Regards,
Christopher Ryan