Do the cradles / hardware TomTom proposes to sell in addition to their software for the iPhone add any functionality aside from external speakers, I wonder?
I am tempted to buy the Navigon software ... but probably will wait til a few reviews trickle in. Best to wait and see really - as TomTom's own release is pending and consumers can make informed choices based on differences between the two packages.
TomTom has said that the cradle has its own GPS chip which it will use instead, and they claim will be more accurate than the built-in GPS. Not sure though if that would only be utilized when using the TomTom software (i.e. if you were using Navigon or something else and mounted it in the cradle, if it would still utilize the cradle's GPS - somehow I doubt it).