Italians, we are an expressive people... sometimes, when I have big ideas, (and those creative juices start flowing) I use my hands and start making (embarrassing) sound effects and somehow, you can present an idea (and amazingly some people understand my "vision").
It's often difficult or frustrating to try write or visually represent ideas, it almost always limits them... there is something lost in the transition from the idea in your head to the description on paper...
...Then along comes mobile technologies and this divide is even more evident. Having spent time designing websites (from the UI all the way to the mainframe) things we mostly straight forward... HTML is fairly limiting on what it allows, (simple form elements, layouts, static images, it's "boxy" layout) and rarely do you deviate from the simple label form element submit button approach.
In mobile, however, things are changing... I took a look at some old requirements documents for a mobile application that we did recently, (it seemed kinda boring based on the document), then I saw the application demoed and it certainly seemed more "alive". In a former life, I worked with the creative team who gave me screenshots for how they wanted a ui to look, I would break things down then slap them into Html in a way that would appease all of the browsers and also look good reguardless of screen resolution or window size. Sometimes you have to make tradeoffs, but (for the most part) you can get things to look pretty spot on. (And for my client at th time, that was good enough)
In mobile, things are different because the "interaction is core to the device"... I say this because you have much less space (on the UI) to deal with, However you have access to all of these tools (compass, accelerometer, GPS, camera...). You don't have a "sedentary person in front of a keyboard and screen" anymore, you have people on the move, and IMHO you need to take advantage of the platform to make an application successful.
Anyways I think we need a new "language" or way of communicating ideas (i.e. customer requirements) so that less is lost between an idea and its implementation in the mobile space, 'cause screenshots and flowcharts leave much to interpretation. (especially with all of the features in these mobile apps (i.e. sounds, vibration, more robust animations, accelerometers, compasses, cameras...)