The new IS Gen5 Navigation unit is awesome, and with its power, screen resolution and bluetooth phone interface... it "could" easily access the web via GPRS/UMTS.
Maybe to update navigation POI's (like TomTom) or for other internet services (mail, browsing, etc).
Obviously the nav unit should have a sort of (permanent) internal storage for these infos, that I do not know if is actually available (an HDD was with Gen1 nav units, dunno with Gen5, other than DVD, that's 'fixed' storage).
Otherwise some updates and customisation could happen by (unofficially) modifying the DVD disk. I don't know if in other ways...
Btw, I cannot well read japanese texts, but... I think - from their website - that some sort of wireless access is indeed available for japanese IS models, together with a *nice* digital TV button...
--> new question: no idea, yet, of aftermarket devices to connect a digital TV tuner to the nice IS screen?
Any ideas?
Ciao,
Gianluca