I've been having this same issue ever since I got an iPad 4. For me it happens in anywhere there is scrolling but it only lasts a few seconds. Very sporadic. Makes me think there is some kind of bug that bogs down the processor every few minutes or something. Probably not worth mentioning to Apple at this point since engineers make you list an exact set of circumstances that these things happen. In this case there are none. It's random.
Same here on an iPad 2 running iOS 6.0.2The only time I notice it is when I'm in the App Store.
It's not bad coding. Apple decided to load the entire page you are viewing in the App Store, so you have to wait for it to load. That minimizes the jitters while scrolling.I think the App Store jitter is something else entirely, this just the App Store being crap now, it dd that on my ipad 2 also. In my opinion they are two different issues, the App Store being bad coding or something.