From the department of excuse-worse-than-crime, Sony Computer Entertainment's Muneki Shimada revealed that the overly expensive proprietary PlayStation Vita memory cards are intended to make piracy harder.
PlayStation Vita memory cards cost 3 to 5 times more than standard SDHC cards, with 4GB cards costing $25, 8GB costing $40, 16GB costing $70, and 32GB costing $120. For comparison, SDHC costs $5 for 4 GB and $40 for 32 GB.
Speaking to Impress Watch, Shimada said that in order to "ensure the security" of PlayStation Vita, the proprietary memory card will not be accessible through PCs as a mass storage device. Instead, users will have to use a special content management program to copy files to and from the PS Vita memory card.
Shimada argued that this approach is actually more convenient for users who wouldn't have to deal with the folder structure on the cards. However, we can argue that having a content management program doesn't contradict with giving access to the cards file structure and giving users more freedom in how they want to manage their content.
As an extra negative, Mac and non-Windows users won't be able to access the PS Vita memory card content until Sony releases the necessary program to their platforms. Shimada promised that a version of the program will be released for Mac OS sometime in the future, but not before launch.