No issues for me so far. But then, I've only had it for a couple of hours now. At least on my iPhone. It's still loading on my iPad.
I did have a couple of minor sync issues when it was loading. The capacity thermometer on the iTunes Summary page for my iPhone (and my iPad) indicated that I had too much stuff. Told me that "other" was too big. Whatever the heck "other" was. I just stopped the sync and restarted it and everything seems to be OK now.
It does take quite a while to do however.
Tom(... wonder what kind of issues those people were having?)