The Memory chart for the 52s is outright wrong.
My guess is that its a ploy to get you to buy the M2 cards, rather than plain ol SD.
Empirical evidence from playing with the phone reviels that the SD card will load and play movies just fine. Music is no problem, and PDF viewing with Pixel is simple.
The thing is, you have to use DIFFERENT methods then the given software to accomplish these goals. Thats it. Its just a superficial software power play to buy sony.
The ONLY lockout I have found, is that Sonic Stage doesn't work without M2.. at least, not yet ;) Where there's an MRE (thats me) theres a way.