Top search bar wonkiness. Zooming in at certain intervals hides content (link to name) that can't be navigated to without continuing to resize further until it appears again. At least in mobile safari on iPhone 4 and iOS 6.whateverthelatestversionis. Other than that, no issues on this awesome update so far.
Sorry, here you go: If you zoom in a bit to fill the screen with the posts, a lot of the nav links disappear off screen and scrolling around with your thumb won't bring them back into view. The only thing that does is zooming back out, or in much further where they will suddenly pop back into view like so: Here I can now click my name again, but I had to zoom in far past the point where the post is readable. See what I'm saying? Not sure if anybody else is running into this.
When you're on your iPhone, and you zoom in there is certain information that is no longer accessible because the top bar overtakes it. I think this may be what ecib is referring to.