It would be stunning for SSDs to take off with exponential speed improvements. Sure, I expect them to get faster and faster, but I have no doubt that there's no Moore's Law at work in this case. I stand by my original comment.
kbob was replying to a post about a "performance boost" and then claimed without qualification that HDs were "on the Moore's Law trajectory"... I didn't invent anything here.
It really depends. Taking a hard black&white stance on other side is just silly.
Say you have an SSD that consists of 8x16GB chips. Internally it's implemented in something like a RAID0 array, which is why they're so fast. If the capacity doubles / size shrinks by a factor of 2 and someone decides to stick 16x16GB chips in the next gen SSD then you will see a speed increase. On the other hand if they go for 8x32GB you won't.