Stocks always drop after announcements that aren't "OMG WE MOBILE NOW BITCHES" in this industry. The fact places like FT and WSJ report this makes me question a lot of what they're trying to accomplish
Based on Wii, 3DS and Wii U, I think you don't need to worry here.
It'll probably allow up to 128GB SD cards. Obviously as it's a portable, it can't have a HDD, and SSDs would jack up the price like crazy so don't expect more than 64GB of onboard memory