Last time I've asked my colleagues from Symbian about updating the compiler used in the Symbian/S60 SDKs the answer was something like ... it's on the list, we're looking into it. I don't know what the status is now but it seems we no longer need to wait for an official release (ok, it depends on how much we're ready to risk "hacking" the SDK).

Forum Nokia user MKechlibar just announced that he has managed to tame the beasts and, judging by the nicely documented Wiki article he wrote, everybody should be able to follow his lead.

Have a look at the article, its title is How to use GCCE 4 with Symbian SDKs, and why not, give it a try!