Sandisk just announced a shipping UHS-II micro-SD card, a first as far as SemiAccurate is aware. With an appropriate reader, this new device should up transfer speeds significantly.
The biggest change to the SD card spec in years is the UHS-II aka SD4.0 bus. The naming may be regressive and painful but the idea of raising the transfer speed cap from 104MBps to 312MBps is a good one. SD sans-Micro cards with UHS-II have been on the market for over a year but the Sandisk Extreme Pro version is the first micro-SD one we are aware of. It looks like this.
64 and 128GB cards plus a reader
As you can see the UHS-II cards need more pins but should be backwards compatible with older busses too. Luckily Sandisk bundles theirs with a USB3 reader so transfer speeds of 250MBps or more are quite possible, more with tuning and a bit of careful tweaking. Even the most untuned setup should blow the doors of a standard SD card which is going to be limited by the bus no matter how fast the underlying flash is.
One interesting side note is that the 64GB card pictured above is clothed in the standard Sandisk livery for the Extreme Pro line, red and black. The 128GB version below it is all red, not two toned. There is a good reason for this, the 128GB version is noticeably thicker than the 64, and the extra layer of paint from the two tone color scheme adds a little bit of height, enough to potentially cause problems with Z-height. This is the long way of saying that the color change isn’t a marketing thing, it has a real technical basis.S|A