Yeah, End stone can be mined normally. It's kinda useless, though. Yes, it has a higher blast resistance than most blocks, but not by much. Only by half. Helps against creepers, I guess, just a little bit.
And it looks quite like the surface of the Moon. It's more yellowish than snow white, but I think I will be using it as a building material for the second iteration of the shrine of the Moon anyway.
And I'm really surprised that the ending comments/credits don't have music to play along with them. They really should IMO.
I don't know. If anything, some of the default music that the player got used to could be forced to play in the background (it was playing at the moment of me jumping into the bedrock portal, so it persisted over the beginning of the ending text), but I don't find it all that necessary. It fits the minimalistic nature of Minecraft, I think.
Oh yeah, that ending. Food for thought. I really had a hard time interpreting what Notch and that guy Julian wrote.
Here is a discussion on the official forums. I think I might read it all eventually just to hear what the others thought of the ending.