I just heard OnOne software, the people who maintain Genuine Fractals (one of my personal favorite Photoshop plugins) now have an iPhone app available for controlling a dSLR remotely.
This thing looks really cool! Getting a graphic image preview and being able to tweak all the camera functions directly from a hand-held remote seems like a step beyond anything we have now.
onOne Software - DSLR Remote for Canon DSLR Cameras & iPhone
I can't think why this would have to be iPhone only, as the iPod can communicate with wifi systems as well.
Also, I don't know whether it can work with any of the integrated wifi camera gadgets. They do say they'll have Nikon support in addition to Canon soon.
By the way, I have no business affiliation with OnOne.
-Noel