We have no plans to write such a port ourselves; none of us has an iPhone, and developing and publishing applications for it looks awkward and expensive. Such a port would probably depend upon the stalled Mac OS X port (see question A.3.6).
However, there is a third-party SSH client for the iPhone and iPod Touch called pTerm, which is apparently based on PuTTY. (This is nothing to do with our similarly-named pterm, which is a standalone terminal emulator for Unix systems; see question A.3.2.)