Address Book/iPhone - Dial with Cell Phone

not yet.

unfortunately, apple has so far decided to cripple bluetooth to only work for headsets. it definitely does seem crazy, though, since this feature in Address Book can work with most other bluetooth phones, but not Apple's own. also, Apple designed iSync for bluetooth syncing between Macs and phones, but the bluetooth in the iPhone will not work with that.

very silly of apple, but i'm fairly confident this will change in a future update. i'd also like incoming call numbers to be displayed on my computer, either through bluetooth, or at least when connected to the Dock. i have a feeling we'll see more of these features once Leopard rolls around.

iPhone has WiFi. I would not want to use Bluetooth for Sync when I have the much faster WiFi.

you can do this with bluephoneelite

bluephoneeilte supports dialing and using the speakerphone on a bluetooth connected mac and iphone. quite slick but i don't feel its stable enough. im sure there's a trial.

there is a 2 week trial for BluePhoneElite 2. It is pretty good but this is something that should be built into osx.