This was my favourite claim from their press release....
""iPhone features the most revolutionary user interface since the mouse. It's an entirely new interface [..] that lets you control everything using only your fingers."
.... so, like a normal phone then?!?
But I'm sure it will cover mms, and much more. You may also like the look of this (or recognise it slightly) which cam out last year...
http://www.openmoko.com/press/index.html
not an iphone I know but at least others are trying.