Third-party programs cannot be installed on iPhone.

According to the presentation of Apple could create the impression that the iPhone will be managed by a full version of OS X, on which you can put any third-party software. As it turned out , third-party software on the iPhone will not be installed, alas and oh. OS X will be severely curtailed, and widgets, anyway, do not pull on the title of full-fledged software.

Confirmation of this from Engadget.

Information obtained in LJ turchinsky