They also never come out and say you have to buy the new rulebooks or need them in any way...
Andy: I think the revised core rules represent the best version of D&D to date, so I guess anyone who's interested in the best D&D experience available should see these books as "vital" for their game. Obviously, following products will rely on these books as well, so players looking to enjoy such products to their fullest extent will want the revised rulebooks on their shelves.
That... certainly seems to be saying that existing players should go out and buy these rules if they want to keep up with this version of the game.
Also to claim the rules in essentials haven't been revised is a little disingenuous at best... regardless of how it was done, they are not the same as the rules in the printed PHB 1 and we won't know to what extent more changes have been made until the essentials books are released.
Ok, here's where I think you may be going astray. I focused on the quote talking about 3.5 being a revision of the rules because
that is what it was, at its core. There was a 3.5 Player's Handbook, and a 3.0 Player's Handbook, and thus one of them was a revised version of the other.
There is a 4E PHB, and there will be some 4E Essentials Books. They aren't a reprint of the previous book with updated rules. They aren't something that existing players need to pick up in order to remain current with the game. They are a book aimed at new players, with all the same core rules, and different (theoretically simpler) builds of the most iconic classes.
Look, I get that until we see the actual rules, I can't definitely prove to you that Essentials isn't going to blindly alter vast sweeping areas of the core rules. I can't prove that all future Wizards products won't completely ignore everything before Essentials.
Now, for those to be true, it would mean that what they have told us so far have been
complete and outright lies. And it would probably be a bad business strategy, and it wouldn't make sense in the context of Essentials. So I'm doubtful.
Your counter seems to be that they said similar things when 3.5 came out. But they didn't, as we can see from the very quotes you've provided.
They've said that the two systems can work together. Now, I don't agree with that myself - but other people in this thread have said that they can, so maybe WotC wasn't entirely wrong on that account. But it certainly wasn't the same level of compatibility as between a core book and a supplement, which is basically what we have here for all existing gamers.
And in those same quotes, they are also being complete honest that 3.5 was a completely revision of the system, and that current players would need to buy it - to purchase new copies of books they already had - in order to remain current with the game and make use of future products.
Ok, I think at this point I'm just repeating myself endlessly, and I don't want to beat this into the ground too far. I'll concede to you, certainly, that until we see Essentials we don't know anything for sure.
But unless WotC reps are lying through their teeth - not just being optimistic, not just trying to spin things to sound good, but
outright weaving complete and total lies - I really don't think there is
anything to worry about for existing gamers.