As far as UI for ported Mac-style apps, thinking out loud, I think it could be done (not ideal but functional) by adding an additional control bar (like most iPhone apps have) just below the iPhone's standard top-bar.
This bar could contain 7 buttons:
* On the left would be 4 modifier buttons for when you click/tap in the app: Control (right-click), Shift, Option, Command (hold to engage temporarily, tap to toggle lock--same way the shift key works in typing I assume).
* After that would be two keyboard buttons--a regular one for typing and one "command keyboard" for one-touch Command-key shortcuts. That version would have an F button instead of its own Shift, with Fkeys, Page up/Down etc. available instead of capital letters, and arrow buttons at the bottom lined up beside a smaller Space. And BOTH versions could be modified by the Ctrl and Option and Shift buttons above, just like when clicking.
* At the far right would be a Menu button that would monetarily add additional layers below the bar--as many as needed to squeeze in all the app's Mac-style menu bar menus. They'd go away again after use.
* Drag and drop or drawing would be done be tap-dragging rather than normal dragging, since normal dragging would scroll as usual for iPhone.
* Pinch gestures could zoom the whole app just like Ctrl-scrolling in Tiger can do (like Universal Access), or be mapped to - and = keys.
It would be reasonably useful and consistent among all apps, and would only require one bar of screen space. Not an ideal setup, but portable.
However, I don't really think ANY Mac apps will ever work by dropping them onto the iPhone--they'll need to be ported, in which case the developer could customize the UI to work LIKE an iPhone app--with iPhone style zooming etc.
And, while iPhone runs OS X, it needs to be noted that it's not _Mac_ OS X. iPhone runs stripped-down version of OS X. They basically took some of the core-technologies of OS X, and run those on the phone. Everything that is not needed on the phone has been dropped. Among those are quite a few critical pieces that the typical Mac-apps need in order to function properly. stuff like windowmanager, dock, menubar and so forth. So while the technology in the iPhone can be found in the Mac OS, not all of the technology found in Mac OS can be found in the iPhone.
Good point. Another reason developers would need to spend porting time.
PS Here's a thread where I've been asking about the TECHNICAL details of iPhone porting--like compiling for a new architecture:
https://forums.macrumors.com/threads/295031/
t.v using its built in wifi.