I thought these things only happened to other people
I've been developing and playing around with the betas from the start and all has been going well.. until my iPhone literally died yesterday. I put it in my pocket (working) and took it out 10 minutes later to find it wouldn't turn on. I figured that my beta had expired (the timing seemed right) so when I got home, I tried to update it.
2 days later, I now believe it is possible to brick a phone. It's dead. I've never believed such posts in the past (noobs...tut.. tut...) but I'm now a believer. You wouldn't believe how many things I've tried and how much I've surfed to try and find an answer. Every time, "Error 1601" I've reinstalled, redownloaded, change USB ports, reinstalled my developer cert, changed cables, changed Macs (twice), downgraded to iTunes 7.5, tried flashing firmware 1.1.4, 2.2.1, used recovery mode, used DFU mode, banged it against the wall mode - I really do believe I have tried everything but to no avail. It's not even jailbroken. All the signs point to a corrupted bootloader (lovely) OR I'm missing something embarrassingly obvious..
Anyway, just a warning to casual users. You may not mess things up as much as I have but there's a possibility of time consuming "hassle"