No doubt about it Grodner needs to go - the show is just so stale and predictable, as are the twists. The only good twist in recent years has been the Coup d'Etat IMO - though even that they had to bring in twice to get it to work.
The show doesn't need to revert to the original format to survive - the basic format is actually fine, but they just need to shake things up along the way. In BBUSA by the time the Veto is done they know exactly how the week will pan out - and they know evictions will go to plan.
The twists need to stay away from being casting related and be more about the core format. The simple rich/poor divide would actually work so well with the BBUSA format and it would make alliances even more interesting when those on the poor side can't plot in secret with those on the rich side (and HoH). They're half way there with the Have Nots - and it wouldn't even take much reconfiguring of the house to implement - basically the Bathroom/spare room can be reconfigured as the poor side and a new bathroom put in one of the existing bedrooms.
Beyond that a series of one-off twists could really shake things up - BBUSA needs to do what BBUK did in series 5 and begin implementing twists which do actually break the fundamental rules and are in some cases actually unfair. Something as simple as having viewers vote in an extra contestant after a week or two - it would be fascinating seeing the two sides of the house compete to win their vote, or whether they unite to get them out. And though the newbies would probably be sequestered before hand, the houseguests wouldn't know that, increasing paranoia and suspicion.
I know back in BB7 I did a series plan for BBUSA off the back of BBUK5/6 with a series of twists throughout. I can't remember the exact details but I know I ripped off the bedsit (the Secret Apartment), with a fake double eviction (I had the HoH nominate three, then a Super Veto where the winner would also pick the replacement) with the viewers voting one of the secret evictees back in - having watched all the action from the house during the week. Another simple twist was the Public Veto - the winner simply got to choose the Veto winner one week.
Oh, and two other ideas I had. Firstly, doubling the jackpot to $1m - but adding the twist that everytime the Veto is used that $100,000 is knocked off. I think I came up with that one when every week they seemed to be using the backdoor strategy for getting people out, rather than nominating them. The other was to add some extra interest to the last few days, especially on the live feeds, and simply have the jury return to the house after the final eviction to judge the final two up close. Much more interesting than a few questions via a satellite link. and really gives the finalists a chance to play the game till the very end.
Considering BBUSA hasn't adopted the twists which kept many traditional BB's going over the last few years I think there is still quite a lot it could do - and I haven't even touched upon implementing elements of Secret Story - every houseguest having a secret is very BBUSA!
They just need rid of Grodner.