I LOVE the idea of a holodeck in 20 years time but doubt that photonic technology will b mastered that quickly that an open and easy to use programming language will b developed
I agree to an extent that as graphics have improved, gameplay has dwindled. However that could potentially change since, as u say yourself, graphics and memory technology probably won't see much of an improvement meaning there is more room for story in games again
My opinion is that as internet speeds and availability increase, along with internet enabled tv's and mobile devices growing in popularity, then all of these will combine to offer an on demand streamed gaming experience.
Playstation, Nintendo, Microsoft will become either service providers which u buy into and receive your content via the medium you choose: tv, pc, mobile device or a dedicated console mobile device. OR they will continue to be the hardware manufacturers of the dedicated (mobile or other) devices and offer the services as mentioned previously.
At the end of the day these guys want to remain in business as long as possible and will try to evolve with the times to do so.
I'm still crossing my fingers that the next generation of consoles will finally have native 1080p requirements, with smooth gameplay (60 fps), perhaps even some PC-side visual options (vsync toggle, AA options, etc), though I doubt we will ever get that much control in console. Maybe graphics options are pointless due due user friendliness and standard hardware in mind, but it would be welcome for those with lower-res sets (720p), or those that would like to output to 720p and enable graphics tweaks.
Console makers just implement currently available components into a console they are designing. I rekon in 20 years the power available and other supporting advancements will make for something much much more advanced than would seem feasable now. Like the jump from snes/megadrive to current ps3/360 games but times 10.
My experience with older consoles is the same, the lasers in optical drives seem to burn out, while the older cartridge based consoles are still going strong. I guess its true inthis case when they say they don't make them like they used to.