Yep - did mine early this morning after downloading and upgrading iTunes to v9.2 on my iMac, and backing up the phone as instructed.
Worked flawlessly...
No halting, apart from the progress bar on the phone remaining almost static for about 4 minutes at one stage - but it kept going without a problem. I assume it was verifying packages at the time.
I luuuuuuuurve iOS4. Here are all of my apps on the one page now. Fantastic. I'm just setting up my VPN connections to work. Multitasking ma have taken a while to come, but it looks to work smarter than any other implementation I've seen in Win, Palm, BB or Android systems. I've yet to see what it does to batteries, but looks and works just great. I also notice that 802.11 performance is
tons better - and YouTube just flies again.