I highly doubt there are two hdd bays in a 13" laptop. Sony is probably using half hieght ssds or something.
just a guess though. it could have 2 bays, I just don't see it being very liekly.
its less than 1 inch thick, so half height ssd's would be what? .4 inch each? a little ridiculous
then again. 2 bays + the optical drive would be like 80% of the laptop. which is also ridiculous.