Aftermarket Head Unit For iPhone...

We are slowly beginning to see specific aftermarket headunits made specifically for iPods, i.e. without cd changers and having a clickwheel like interface that will show a songs name, artist, and even album art! This is great, but since I got my new iPhone, I want my car to be maxed out. I have an 02 Xterra. I have already put about $1500 into its sound system but still have a crappy old aftermarket head unit in there thats about 3 years old. Its a double-din (extra big) space for a headunit, so do you guys know of anything that will do this? Basically act as the center as of my car... Allow me to connect my iPhone to it and use it as an ipod in that I can play all my music and the songs info will come up (preferrably with album art), and then when a call comes, the music will pause, the contact will come up on the screen and i can answer it with my bluetooth headset? (hence I guess i need the radio to have bluetooth as well...?) And finally, I've never had a navigation system so the turn by turn directions on the iphone are the best i've ever gotten (and believe me, I use them ALL THE TIME!)... So I know this is a ton of "required specs" and my instinct tells me there is nothing like this right now, but what do you guys think? Is this something realistic in the future? I mean, can I expect to start seeing things like this?