If Apple continues to deny there's an issue - there "no" issue. I'm not saying there isn't an issue. Don't misunderstand me.
What I'm saying is - If Apple says there's no issue. And they do not change the phone. The phone is the phone is the phone. Defect or not. They've endured the worst of the press they can get for now.
*IF* they change the iPhone 4 design - they will enter themselves into an even bigger crapstorm with PR than even before. They will also be admitting to the public that they lied and that there's been an issue all along. "Political Suicide"
The cost of keeping things status quo at this point would be cheaper than the alternative. Better to have the iPhone 4 sell like crazy and be considered flawed than go through the legal and public opinion battle by changing it.
The time to change the design has passed. If they had any intention it would have been before the press conference and/or announced at the press conference before they presented "facts" that disputed any design flaw.
But again - if it helps you sleep at night - feel free to think the iPhone 4 design will change.