I'm dubious about MSFT having multiple SKU this time around, some leaks makes clear that at least at some point Durango was to be "disk free" I mean the game got installed and then the disk is no longer needed during gameplay. Games are to be on BRD and the size is too big for flash to be an option, if there are SKU they all going to have a healthy HDD.
Then there the leak about Kinect being part of every SKU.
Overall without new information I don't see on which aspect of the design could make cut to have different SKU in a significantly different price brackets as they did with the 360.
I do agree that 399$ is a sexy price tag but 449$ for example is not that much more.
The problem I see is that this neither Sony or MSFT should benefit from rapid decrease in BOM through shrink/hardware revision.
That is why I was wondering elsewhere if they could redesign the 360 (more than a shrink) to have a compliant low end SKU ( I think they definitely can, software/BC is the real issue here).
The other important thing is I don't know what they can add besides hard drive space to create a higher tier SKU. This isn't 2005-6, you can't try and sell a console without WiFi anymore without being laughed at. And if games have to be installed, having anemicly small hard drives will be ridiculed. And what has to be really scary is that because both consoles are coming out at the same time, they will be DIRECTLY compared. So if Microsoft tries to pull another proprietary hard drive on us, that's one more point for Sony. Even though we have Xbox Live and PSN, I still think the network effect resets to some extent, especially if one company pulls some BS on uses (see always-on threads on neogaf).