I think upgradability is way oversold as an attribute. In theory, it would appear to be very beneficial, but in reality it seems to have mixed results. There's no doubt that new models cause old models to depreciate overnight, but they don't perform any worse in the morning. Upgradability can certainly extend the life of a component, but there are definite limits. One other form of upgradability I'll throw on the table is Lexicon's - they have very competitive trade-up offers when they bring out new models.
Is Component "Upgradability" Important ?
I have always been concerned when buying a component that it can be upgraded by the manufacturer at a later date if a new version comes out but I am starting to wonder if this is really that important. I say this because manufacturers are hardly willing to give away upgrades just because you may have purchased an earlier version of their product. It seems as though you will end up spending the same amount of money whether you pay for the conversion to the new model or you sell your old component and put the money towards the cost of a completely new model. I am not sure what is the best way to go for the manufacturer but I am also not sure that having one model physically converted into another model is always the less costly way to go for the consumer.