There's nothing wrong with improvement. Give all the classes something as they go up in level, good. Make all the classes more useful, good. Make all the classes equally and uniquly useful, not for me. What's wrong with overlap?
-- SOME overlap is probably all right, depending on specifics. I think one thing that's nice I've seen so far in 4e is attention being given to the role of a character within the party, as something that transcends class and race and so on. Within those roles, I imagine there may still be overlap between classes. A Healer druid and a Healer cleric may have many similarities, for example. At this point it's hard to draw any real conclusions though.
What's wrong with a bard being a generalist but a master of none?
-- It makes the bard a kind of silly thing to include, mainly. I've never seen a bard used this way though. Typically bards have been masters of social arenas...which still can be an issue, depending on the game and other players...and decent support with their music and occasional healing. I've seen bards played well that did just fine. I've also played a bard, but didn't find it very rewarding. They don't suit my play style very well, except by being very vocal.
What's wrong with simply reinventing the gnome by drawing on other fantasy sources as opposed getting rid of a core race?
-- Do we know they're getting rid of it, or are we assuming?
It sounds like elves are being reimagined. GREAT! Why can't they do that with gnomes?
-- See above.
Why are they adding in a Warforged (which is not a generic fantasy race)?
-- ...also see above.
They're changing fighters to progressively more useful. GREAT! Why can't they do that with bards?
-- See, I thought they WERE.

In fact, I thought I saw a quote that specifically said that bards wouldn't suck anymore. So I'm not sure where you're coming from.
They're making wizards power more evenly spread over the whole class. Eh, ok fine. Why can't they do that within the preexisting system of 9 spell levels and X number of spells per day?
-- Maybe they could, but you have to admit that system carries a lot of presumptions that limit game design. Is there a real reason they should stick to those limitations? Do those limits make the game more, or less fun?
Why do they have to scrap several editions of system?
-- I don't know I'd say they HAVE to scrap previous editions, nor would I say they are. A new edition gives them, and us, an opportunity to apply lessons learned insofar as what works and what doesn't. It builds on past editions, without being limited to them.
Why do wizards have to be always useful, all the time?
-- Because that's more fun than being necessary once or twice, then useless?
Wizards are suppose to be more difficult to play.
-- That's a design decision. One that they (and I) apparently disagree with.
Your reward for playing something more difficult: a more powerful character.
-- See above.
Really though...it's too soon to be flying off the handle. Lets save the vitriol until the rumors are over and we really learn what's going to be done. THEN we can bust out the torches and go mob Wizards.
