My Experience.
elenex50,
I JUST did this about 2 hours ago on a brand new OTB 16GB iPhone. Here's what I did:
1. So I unboxed the 16GB iPhone and plugged in the cable to my windows box with the following installed:
Windows XP Professional (fresh install with ALL the updates critical and optional)
iTunes 7.6.0.29
ZiPhone 2.4 (the newest GUI included version)
2. The iPhone was recognized by the computer, but iTunes didn't launch or anything.
3. I manually launched iTunes and was greeted by the AT&T Setup prompt. I left it there. Didn't hit cancel or eject the iPhone. Just left it as is.
4. Opened a command prompt window in the ZiPhone directory, and entered the command: "ziphone -a -j -u" and hit enter.
5. ZiPhone started, found the iPhone, and put it into recovery mode all automatically.
6. All the BSD gobbly gook started rolling by on the iPhone's screen. I waited. Approx 4 minutes.
7. It eventually rebooted the iPhone, and the command window stated "Done!" and was back to the prompt.
8. I was able to "slide to unlock" on the iPhone screen and was greeted with the first message telling me about the Home screen.
9. From there I shut down the iPhone by holding the sleep/wake button and installed my SIM (Rogers Communication).
10. Turned the iPhone back on and the iPhone found the Rogers network and I began testing: connected to WiFi, browsed through Safari, sent an SMS message, dialed out, received a call, tested YouTube, tested camera, etc etc.
That's it! So far so good.
I hope that helps!