I must be doing something different, because performing your exact test doesn't have the results you describe. I just opened a CNET article on my latest-gen iP

I must be doing something different, because performing your exact test doesn't have the results you describe. I just opened a CNET article on my latest-gen iPod Touch running iOS 6. When the page was half-loaded (header loaded in, no content yet), I placed my finger on the page and dragged it a couple pixels. I left it there for 30 seconds - nothing on the page changed during this time - then removed my finger. I then very clearly watched the story header image progressively download, and it took several more seconds for the page to become fully rendered.