For a company, the most important factor is likely money and so reverse shipment is unlikely to ever gain widespread use. It’s simply too expensive for them to disassemble an old machine in order to reuse parts of it. By coercing manufactorers to accept old equipment for recycling or disposal, we will end up paying for it ourselves in the end (since it just means the price of the equipment will go back up). I think that it’s definitely worth it and would love to see such legislation and in some areas (such as battery disposal) this has already been done to a certain extent. It is a difficult road to travel though.

As a consumer, load times and performance is probably what matters most. If the machine appears to be fast (fast enough for your particular needs anyway) then it’s usable. If not, it will be replaced once the annoyance of wait times and slowness outweighs the price of a new machine. And as you pointed out, when the price goes down it takes less for us to dump the old machine and buy a new one. The concept of blowing new life into old machines by installing linux stems from the reduction is slowness it is able to provide (and the host of usability improvements it offers).

The green factor of equipment has become more and more important over the last few years. And with this in mind refurbishing old, powerhungry machines could turn out to be both more expensive and more polluting in the long run. Which approach is best generally depends on the age and configuration of the specific machine. Since this is balanced by the pollution that is generated as a consequence of the production of the machine, you’d have to analyse individual machines’ power-consumption vs. its production-caused pollution compared to newer machines in order to figure out what the best cause of action is. Perhaps it would be a good idea to have the vendors supply the information about their production process needed to make this assessment.

At the end of the day though, the most likely way to reduce the resource misuse is by use of a carrot and a stick to give manufactorers the incentive to improve in these areas, to fund publicly available research into improved methods for production of electronic equipment and maybe to look into new materials that are easier to dispose of than what we currently use. One thing is pretty certain though: I don’t see our rate of computer usage and investments in new equipment going down. People want the latest and greatest software and hardware so the average lifespan of a computer is probably nigh impossible to improve.