But gods forbid we don't say that the PHB has been "replaced".
Well, since they indicated it wasn't going out of print I wouldn't say "replaced" either.
It might not be as important for new players, sure, but not replaced.
Maybe it's place in the game has been modified?
Now it kinhd of I'd say sits in a similar place to some of the splat books. More options for players of the game.
Looking forward, I don't think we can really be sure how the fighter that uses daily powers will return to an updated print product.
Since the book is still out there, and they've indicated new print runs will happen when needed, I think this is just a matter of if the player sees the book, thinks the concepts are cool, then he will probably buy said book.
Just like every other game book out there.
I really doubt I'm a weirdo when it comes to my buying habits- I remember when I was playing 2e AD&D and buying Unearthed Arcana because I thought the Barbarian was a cool class.
Buying the PHBI and using the stuff in it is even easier because it's even designed for the same game.
Players buy stuff because they think it's cool.
We argue about how new books will effect those players because... We think it's cool? I dunno.