D&D 4E How would you re-envision Planescape with 4e?

[Steely Dan]

I thought there was also an ethereal plane

We've heard no mention of an Ethereal plane in the 4th Ed cosmology that I'm aware of. I believe the only planes, or whatever they are called now, that have been mentioned are the Astral Sea, the Feywild, the Shadowfell, the Elemental Chaos (which included the Abyss) and Dominions (Hell etc) that float in the Astral.

 

[Najo]

Ok, low level planar adventuring. Starting characters in the planes.

1) What do you do to make this work?

2) What sort adventures do players go on?

What changes to the planescape cosmology or D&D rules to make these two design constraints work better than in previous editions?