Yeah, I agree that discovering the scrolling nature of the iPhone's typeface list is not immediate for every user. Of course, that's a problem with most scrollable lists on iOS (and now Lion--cf. John Siracusa's comments on Hypercritical #27 about pawing at everything on the screen).

On the iPad, the list displays 4.5 lines, with the top of 'Meta' peeking up from the bottom, so that's a natural visual cue that the list continues. Perhaps there's room to fit in 3.5 (3.4?) lines on the iPhone app, but I would be concerned about making the list either too cramped or unbalanced next to the triad of buttons on the right. In any case, once one discovers that the list scrolls, it's hard to forget it, so perhaps it's fair to trade discoverability for a cleaner interface in the long run.

One additional minor flaw I noted on that list (iPhone and iPad alike): the 'Lyon' text looks like it's aligned too high. I suspect the descender on the 'y' is to blame, although I don't see the same problem with the item for Georgia, the only other font with a descender in its name. One-star review until it's fixed in 4.1.1! ;)

P.S. Glad to hear the appreciation for Minion--I was so happy the day I got my TeX installation configured to use it. I'll likely wait for the 4th generation to update my iPad 2, so Marco's got a year to hash out an agreement with Adobe to use it....