Man, I'm gone for a couple of weeks and I almost miss this topic!
I don't agree with the car analogy. The fact is, if you take care of a car and change the failing parts religiously, you can essentially keep it running forever. I know. I worked on a car last week that nearly triples my own age! And it purred (but not as well as you, Feline

).
I think the human body falls into the same category. This topic has been beaten to death on a few other forums, but technology will eventually get us to a place where virtual immortality will be possible, even commonplace.
Me, I wish it would happen soon (noticed a bald spot forming on the back of my head the other day

). Personally, I can think of a hundred thousand things I'd like to do that I never seem to have the time for. So I think boredom, while inevitable, would be a *long* way off (at least several hundred, perhaps even thousands, of years).
The trick, as has been pointed out, is economics. I fear we'll reach that technological point of virtual immortality before we reach the social maturity to handle it well. So they'll be a massive purging, which in and of itself will act to equalize things out a bit.
But evetually, as has also been stated, we'll adapt, grow, mature to handle it. With that technology will come others designed to stave off the boredom. We'll travel into outer space, or begin to develop inticate and fully realistic virtual worlds, or both. There will be plenty to keep us busy.
In the end, though, there will be a point at which boredom will take root, and at that point a voluntary suicide will probably be the way of things. By the time that would happen, I imagine it would be considered socially accpetable.
All this, of course, assuming we don't blow up, strip mine, pollute, or infest the planet to the point that we're extinct in the mean time.