sevenbastard
Hero
The presentation in the DMG is just that: they start with a manageable hub in Greyhawk itself, and spread it out from there, precisely as an example of how to start small and build out.
I think even showing the whole world of Greyhawk is a mistake as is a big city vs a medium village as a starting point. I feel this is for nostalgia vs actually use as a good example for DMs.
Again all of this is my opinion, but small region, tons of rumors, multiple adventure sites, fraction with goals, limited authority to help or hinder the PCs, is the way I start a campaign.
I'll reserve judgement until I see it, but I've been let down by Mr. Perkins and the WOTC marketing arm to many times.