If you have an iPad, viewing these images will give you an idea of what a 7" iPad would look like
http://seveneightyfive.fscked.com/
Note that you have to use an iPad to view these, since they are calibrated to the physical size and pixel density of the iPad.
So it's interesting - some apps, like Flipboard, clearly look quite usable in a 7" iOS form-factor unmodified. Others, like Tweetbot, look problematic with the extremely small buttons on the left hand side. A lot of the links and buttons in a Safari web page look too small to me to be easily targeted, but you can pinch to zoom in, so I consider that a less serious issue.
It definitely illustrates the hypocrite's point - some of the tap targets are extremely small, to the point with an app like tweetbot that I think you'd want an interface re-design for a smaller form factor. On the other hand, plenty of apps look like they'd be generally pretty usable un-modified on a smaller iPad form factor.