At this point I believe there will not be an iOS update until the "big announcement" next month, which may include such things as a new iPod touch with iPhone 4 like capabilities, a new $99 iTV with iOS, and maybe a downsized iPad. The reason I bring this up is that they will not release the new version of iOS until the cat is officially out of the bag, because the new iOS will contain obvious clues to those products.
In short, you can't have your proximity fix now or for the next month. And the biggest reason for this is that Apple has a marketing schedule to hold to.