Western Digital (who recently bought Sandisk) introduced a new suite of 256 gigabyte (GB) microSD cards, which includes the new 256GB SanDisk Extreme microSDXC UHS-I card - the fastest microSD card in... Western Digital Launches 256GB microSD Card capable of 100 MBps
I'm pretty keen for faster high capacity cards, copying between devices can be very tedious. Although I wish we had the technology for 512gb micro ssd cards already.
We do have the technology. Or at least Microdia apparently has it. We'll see when (if) they launch such a card in July like they said they will. http://www.cnet.com/news/microdia-will-sell-a-1000-ish-512gb-microsd-come-july/