[alirazaq]

So progress should be avoided if it means throwing away everything else?

I can see Android rolling this out across two major releases. The first adding support for a new VM or app language and the second removing Java. Time between those releases will give developers the chance to catch up.

I just think it's silly that you are opposed to throwing everything away. That is what got us in this mess to begin with. Android was supposed to be a simple transition for existing J2ME devs.

[V-2]

Ditching rich pre-existing ecosystem by itself certainly isn't progress. The greatest language without that ecosystem is like the shiniest OS with no apps. This includes communities, developers who've acquired enormous amounts of know-how by now... It would be extremely hard make this trade-off worth it. A tough call, and a multibillion dolar company will think more than twice before choosing that route. I know I would

"I just think it's silly that you are opposed to throwing everything away"

That may be, but I'm pretty sure Google wouldn't think so :)

[vetinari]

It took Apple 12 years to deprecate Carbon API. It is still being shipped for compatibility.

Nobody really throws away anything, that other people are depending on. Especially, if you are depending on their continued investment into your platform.

Otherwise, Windows Mobile to Windows Phone happens. Or Python2 to Python3 (how many years it is already taking?)

So two major releases is too optimistic. Especially in android world, where more than two major releases are used simultaneously.