It's a most marvellous speech (so is the one - which may be the same one? - about language). I saw a production of Tempest years ago,when I was young and impressionable, which blew me away with its poignancy, and the utter loveliness of Miranda's words and mine, with my heart in it. (a notion which I stole for a fanfic a couple of years ago.)

No, agreed - if we took Caliban out of the fairy-tale, I can't see that there could have been a happy future for him back in algiers. I think his life on the island alone was too brutish to be called happy, but at least not malicious or resentful, so in that (and also in not being forced to labour) happier than when Prospero arrived. Whether he can be happy in the play's future is unclear - there's no going back to unthinking, and he doesn't (that I can recall) get to the grace of being able to forgive.

If I had to guess, I'd think that he spent time post-Prospero resentfully waiting for (decoying?) another wreck, and then being much more cunning with the survivors. Which is an idea I like the thought of, very much - I mean that as the start of a story, thinking how one would get from that to a happy ending. Someone's written a book called Caliban (stopping to check,now). No, all I can see in a hasty look is a SF book about asimov-style robots. But there must be more.