People seemed concerned that they have to get the phones back to Apple within 30 days to get a refund. Ok, I am in the UK and don't know if the same applies in the US, but would assume it probably does.
My 30 days is up next Friday, and i have to say that to date (including traveling around the UK) I cannot replicate the loss of signal issue to the extent that the call is dropped. However I did have the issue on the proximity sensor, which appears to have been resolved by a reinstall of the software and setting up the iphone as a new phone rather than restoring from my old 3G.
That said,, and given what is clearing available in the public domain , that there is an admitted issue with both the signal and proximity sensor, it is quite reasonable behaviour to wait until the manufactuers fix is released to see if that works. if it does not, then under UK law, the user would still be entitled to return the goods and 'not fit for purpose' and have a full refund.
Whilst Apple may well try and refute the obligation to a refund, then the threat, or issue of a claim in the Small Claim Court, will, I guarantee, result in a satisfactory settlement for the user.
Whilst the manufacture of any product m,ay issue terms and conditions, these CANNOT over-ride national legislation which, as I have stated, says that goods must be fit for purpose. I think in the US its called 'a lemon'. Perhaps someone from the US will advise.
That said, there is therefore no-one who needs to panic or get so stressed about getting their phone back befofre the 30 days is up. Sit back, give Apple a reasonable time to fix the issues, and if they dont, then clearly they will have to replace the phone with one that does actually work, or refund the full cost.