Hi Neil,
Welcome to the LinuxMCE community!
Theoretically you can run Java-based Orbiter on the E63. I don't think that the native S60 Orbiter will be ported to the OS 9.2 (it even doesn't work on S60 3rd edition). Regarding to other mobile platforms. As I know the iPhone Orbiter is almost ready (but I didn't see any example of its using) and Android Orbiter is in the development. Also there is an universal web Orbiter which can work on the wide range of devices.
Thanks nite_man. I'll take that as a definite maybe. If I do end up getting it I'll have a go at making it into an orbiter at some point. The Asterisk VoIP option seems to work from what I have seen on Google.