MCE Technologies (http://www.mcetech.com) is shipping a 1TB and a 500GB Flash Drive Upgrade Kit for the 13-inch and 15-inch MacBook Pro with Retina Display (mid 2012 – early 2013).
Each kit includes a USB 3.0 enclosure for the original flash drive to facilitate data transfer, all tools required to perform the installation, an illustrated installation guide, and drive cloning software. The 1TB Flash Drive Kit retails for US$479 and the 500GB Kit for $279.
The upgrade kits install in place of the existing flash drive in the Mac laptops. They’re based on the SATA-III architecture in those machines and can transfer data at speeds of up to 550MB/sec when reading, and 520MB/sec when writing.