Ovi Maps 3.3 is already available for E72, E55, E52, 6730, 6710 (S60 3rd Edition Feature Pack 2) and all of Nokia's Symbian^1 (S60 5th Edition) devices. Other S60 3.2 devices may follow; S60 3.1 or earlier devices are unlikely to be supported (but have had a license price drop), although there is no official confirmation from Nokia on this.
Currently the N86 update is not listed on the Nokia Maps website, though this is likely to change in due course.
A few users have said that the compass function does not work on the N86. This is not the case: once you have a GPS location lock press '5' which will rotate the map according to the compass (pressing it again switches the map view back to 'North up'). You may need to calibrate the compass by waving the phone around in the air in a figure of eight motion. You may temporarily lose the compass lock when you close or open the slide - another quick phone wave should sort you out!
Ovi Maps on the N86
Thanks to andrewjheatley for alerting us to this. Do let us know if your phone has recently gained Ovi Maps support.