This is (was?) an intriguing thread (is it dead yet?) - I can't believe I read the whole thing!
I've been lurking for awhile, and this thread compelled me to register and respond.
As far as dead or dying hobbies go, I'll have to second the opinions on dice & paper role-playing games and wood carving/whittling. And yes, I'll also chime in on blaming video games & the internet for their demise.
But - as for modeling dying out, I think not. At least I hope not.
As others have suggested, there is good reason to believe that model building, like other hobbies, are cyclical in nature. I grew up in the early 80s - and was an early PC and video game user. I also had many hands-on hobbies that were gradually replaced by those techno-toys (and by girls and cars, but that's another subject altogether)
But now, having spent years as a hard-core video gamer, plus working 40 hrs+/week with my nose 20 inches from a computer screen, I NEED to take a break from the techno-toys. I HAVE TO spend time working with my hands or else I'll go crazy. I MUST create and build and construct to keep my mind and spirit activated.
I have a 2.5 yr old, who certainly loves watching his TV - but his favorite place in the house is Dada's Workshop. He even has a little 'tool table' I made for him that he plays with while I tinker on the workbench. I am dedicated to showing him the positive aspects of unplugging.
The only way to perpetuate this hobby is by sharing your love of it with the next generation of modelers. There are so many ways to keep family members isolated behind their individual devices - we must be proactive in breaking down those divisions and spend more quality time together. Modeling is but one of a myriad of vehicles for attaining that goal, hobbies in general are so important - and one our modern society has taken for granted.
OK, that was verbose... I was afraid of that.