I never said it was or was not an issue in iOS6. I merely stated that there are many more threads about very similar issues many of which are unrelated to any iOS update and provided some steps to troubleshoot.
Place blame where you want, wait on Apple to fix it (if an issue exists), or be proactive and take steps to resolve the issue now.
Frankly, until you rule out basic troubleshooting, declaring the issue as an "iOS6 update issue" is not very smart.
As noted by BubbleSheep, the headphone trick rectified their issue, which leads me to believe it is not an iOS6 issue. If it were, a basic troubleshooting step would not resolve it, and there would be thousands, if not millions of users experiencing the same issue... a dozen or so people in one thread having a similar issue does not make for a software bug.