I guess new 7er will be better than W221 S-class. It will be lighter due extensive use of light weight materials, interior materials quality will be further improved, it will come with extra powerful turbo engines, enhanched gearbox, modern design, latest hi-tech features, much improved iDrive.

Taking different styling and also engineering directions for SWB and LWB will allow BMW to make SWB much more sportier than S-class and A8, and the LWB much more comfortable and luxurious.

But again, when next generation of A8 will come out, it will beat both, 7er and S-class. It's just a characteristic of techincal progress.
3er segment is another story, because it's more diffucult to reacha perfect balance between sportiness, comfort ride, space, etc.

About Scott26: the guy has an access to many internal BMW information. Therefore I suspect he works either in a marketing or PR department.

But you should mind the info he dispetches to us are not official press material, but working material - and so an object to change.

I guess BMW have issued an internal paper "Project F01 / 02" where some design proposals are illustrated, engineering goals, marketing goals are listed, etc.

New car development is a dynamic proces - where difficulties may occure: of engineering, design, legislation, marketing, financial nature. An issue have to be addressed quickly, and changes have to be made.

It's 2-3 years too early to know how exactly new 7er will look like, and what it will feature. But again, Scott26's info give us an idea what BMW is aming to.