The latest firmware updates and the latest models with Symbian, have in common that are not hackeables. You can not modify the phone to accept unsigned applications or using the patch ROM. For now.
Symbian hackers are still working, and apparently has discovered a new vulnerability in the platform of security-related mapping of virtual drives. This makes it possible to access the protected file system and install programs to hack the phone. Its discoverer, Deltafox ensures that works on a Nokia N82 and has published the method for those who want to check on their mobiles.
Some people only see this kind of hacks road access to pirated programs. Others, however, given the extreme personalization of your phone through the operating system patches officer. To me, what I would like to know is if a hacker is more attractive to devote their time and knowledge to a closed or open platform.