It's a good thing that Apple is trying different things with the UI. If they didn't "think different," they wouldn't be Apple. The HIG aren't set in stone. It's better for the apps to take a life of their own, see what works, and adapt the HIG to what worked after the fact (which is how we got the HIG in the first place). We wouldn't want the HIG to change every time just because Apple tried something different with their widgets. The nice thing about HCI is that no matter how much technology becomes obsolete, the basics of HCI never do. Look at the HIG as a basis and guiding track, not as a bible or absolute truth. And as Scott said perfectly, just do whatever seems right to you.