Call it blu-ray because that is what it is. If you just want a new codec with the same media you need some DVD2 label and get DVD player manufacturers onboard with the new spec so that players are common before the first disc. Also because consumers are not happy about replacing their DVD players all the time you have to not create new specs too often. (or perhaps you can have a standard decoder cartridge which can be put into your existing DVD players and sells for $5 thus making upgrading to DVD3 not a big deal). there are lots of options, but the point is always don't make it too hard for consumers to know their DVDs and drives are compatible.
There were TVs made that you could upgrade the processor on, they were more expensive and never took off.
People want cheap, they'll forgo the better product if they can get one that's on sale cheap. Consumer choice says that an upgradable product sells worse and the company that makes the upgradeable models will get the lowest market share.
You'd have to legislate modularity and then you get people complaining about government over reach.
