when I bought my N900 I really did not even think about the possibility it not having voice guided navigation. Turn by turn navigation + no voice, is no safe way to navigate and drive. Should actually be prohibited by law. I compare it to reading SMS while driving.
I just hope that my smartphone e71 (which I by the way use as phone, not N900- being an early adopter of 770 after waiting for a 3G version for 5 years) gets free navigation...