So Apple has apparently released iOS 4.01 with a New Reception Formula.

Version 4.01 (8A306) was released earlier today.
I’m now running iOS 4.01 on Carrier AT&T 7.0.

Even on the iPhone 3GS, it appears that I now have one less bar than I did before the update, went from 4 bars to 3.
iOS 4.0.1 can be downloaded in iTunes and is compatible with the iPhone 3G, iPhone 3GS, and iPhone 4.
The bars for signal strength appear to be a little larger and/or spaced out a little more.

iOS 4.01, iPad 3.2.1 Released (Download Links) https://bit.ly/bgqiB4

This update is supposed to update the phones especially the iPhone 4 so that it more “accurately reports signal strength. So in my case there will be no bars like before…

Sounds like this update could be part of the solution for iPhone 4 owners.  Along with the bumpers to cure the antenna issues.  We will see.

It seems that Apple is still working on what will be said and released at the press conference, but we are hearing reports that it could be a bumper credit and discuss the iOS 4.01 update.

The iOS 4.01 update does nothing to improve reception, basically it just reports more “accurately” what the current signal strength is.