Only 1.7 million won't be, a very small percentage is actually vocal about their problems which is why I think this whole thing will be swept under the rug and forgotten about.
It's become a non issue for me as I've been using my phone flawlessly since day one. Those that aren't so lucky will probably just have to return it.
Return it yes... But when to do so is the real question...?
If this problem is rectified by a hardwae change in future iphone 4s.... then surely apple will have to effectively recall everyphone produced before a certain date, if only to avoid a mass of law suits.
With Websites tearing apart tech to see how it works there will be no way of Apple hiding a hardware change.