i don't see it that way - in fact i dare to call "keep them separate" claims silly.
integration is what has brought low prices and high availability of any product (and specially electronics).
memory and memory controller integrated in cpu don't cost much and since part of the cpu, get replaced together with cpu.
just because there is some cache on the cpu, or some flash memory on some new digital camera (just to make point), it does not mean that you cannot add more ram (on computer) or larger storage (SD card for example in case of camera).
for those who don't remember, there was a time where cache was not integrated in cpu. it was damn expensive and often costed more than cpu.
there was time when CD drive needed dedicated controller (before they could attach to IDE for example) and it would occupy mobo slot. aneedless to say it was cluther, with slow performance and high cost.
there was also time when chipset was just that -> collection of few dozens chips (a set) performing only few very basic functions (didn't include modem, serial or parallel port, network card, sound card, hdd or fdd controller etc. - think about what comes in today's moos or the north and south bridge).
my first network card, sound card, modem etc. costed each about same as the CPU of the day. nowdays those things are part of chipset/motherboard just like video output which may not be faster than discrete card but it's good enough for 95% of applications and - it's "free". and just because there is onboard video, nobody says that you can't add another graphic card (or two, or three...).
another thing is with integration, many things can be resolved more efficiently including size, power consumption, foootprint, bandwith etc.
so AMD and Intel, please make my next pc small, size of a dime sounds about right as i would like to carry it around without straining my arm. heck, integrate it into glasses that can double as high definition monitor.