I agree with you on needing to have the OS on a flash storage. However, smaller loading times is a high priority for me and as such I would rather have an SSD.
Various benchmarks have shown that games on the PS3 have anything from very slightly shorter to signifcantly shorter loading times. And this is on a console that was never built, or at least optimized to work with such hardware. PS4 will surely be prepared to take advantage of all the benefits that SSD's provide.








