With all that said, above, would I like to see a Greyhawk reboot in this style?
NO. I really wouldn't.
Why? Two reasons:
1) I'd rather see something new. They're sitting on TWO, count 'em, TWO settings that lost to Eberron in the design project, both good enough to make it to the final three. Both could be made from scratch in 4e's image as they pleased.
2) Greyhawk is such that its fans are so divided in desire, as this thread makes evident, that no one can please them fully. Greyhawk is this family Teddy Bear that started out brand new and whole, then got a bit worn on the edges, and the sadistic brother tore the stuffing out, so Dad re-stuffed it, cut out the torn up parts and sewed it back together, to have it get hit by lightning, then repatched, then left in the driveway and backed over by the family SUV, then repatched, etc.... until it's a third of its original size, has buttons for eyes, and a bunch of fans caring for it out of memory for what it represented to them. Leave the damn bear alone, and go get a new one.

Let the fans argue over what the original color of the teddy bear was, or where its eyes are really supposed to go, or what material the original stuffing was made from...