Just released - the design patent on Northrop Grumman's Next Generation Bomber concept.
Details: as expected, it looks smaller than a B-2. Four engines make life easier for the signatures group, because the smaller inlet duct can achieve the required radar-blocking curvature in a lesser length. Most likely, a single weapon bay on the centerline. And, as expected, a variation on the Northrop Grumman "cranked kite" planform family. And, overall, not too far from the concept that Jozef Gatial produced for us last year:

Jozef Gatial for DTI
No wonder I was getting some odd looks from Northrop Grumman people. Another observation: some of the names on the patent are relative newcomers, this being their first patent for the company. The patent was filed at the end of 2007 - just before Northrop Grumman reported a major contract win, probably associated with the NGB project. For more background to the bomber project, start here.
1) what was patentable in that general design...
2) why to patent something that should be kept in most secrecy
As for the secrecy, I think this could be a signal that it will not prevail for long.
I always thought it would make sense to put these weapons on a super stealthly platform that could creep close to borders thereby extending the intercept range of carried missiles as far inland as possible.
I sure hope it is!!
The F-15? ..... too small for the Thaad .....
http://upload.wikimedia.org/wikipedia/commons/thumb/7/71/Wfm_thaad_diagram.svg/790px-Wfm_thaad_diagram.svg.png
Surely a larger, and stealthier, platform, as you stated, could be more suitable .....
But I'm in the camp sferrin defends, i.e., favoring NCADE over the PAC-3 variant. Besides, NCADE is F-22/F-35 internally carried, while wing-mounted PAC-3 would alter the calculus some.
Re: NGB... it should absolutely be designed per spec, around carrying a single 'Massive Ordnance Penatrator' size munition, otherwise 50% of it's deterrence would be forfeited IMO, and it would hence be more logical to go with higher performance, operationally flexible, econo FB- alternative IMHO (as others have voiced).