While something like the U.S. vs the world would be interesting... like golf has their different tournaments, I think it could still stay Raw vs Smackdown. However, there is a change that I would make to the whole concept.
It should be a best of 7 series, with some sort of bigger reward (other then the BR Cup) to be used at a later date...
WWE Champ vs World Champ
I.C. Champ vs U.S. Champ
Raw vs Smackdown Divas Match (could be one-on-one for title or a tag match)
Then the 7 on 7 team concept...
Team captains or GMs set up on the stage like they do on NXT. Raw sitting on one side, Smackdown on the other. Bring out the Raw Roulette Wheel to decide the format of the other 4 matches of the night. Have a ref then flip a coin to see who gets the match advantage (picking the match participants).
Example using this year's teams...
Match #1... Bodyslam Challenge (Smackdown wins advantage)
Big Show would pick himself vs Santino to get an easy point for SD
Match #2... Tag team Match (Raw wins advantage)
Miz would pick Rey and Del Rio (since they hate each other) against anyone from his side betting on SD team not working well together
Match #3... $70,000 Ladder Match. (Raw wins advantage)
Miz would get to choose who is in the match. He would make the match CM Punk (with 2 MITB wins) vs Reks (due to his lack of experience in ladder matches)
Match #4... War Games with remaining team members (Smackdown wins advantage to go in last)
This would be the match that would decide who wins the trophy... and Bragging Rights
I know that was a little drawn out, and won't likely happen. At the same time it would be better then the 7-on-7 one fall to a finish tag match crap they are doing again.
Thoughts....