It's been known that the first iterations of the Symbian Foundation's platform releases are basically going to amount to S60 5th Edition
Feature Packs, but what comes after that? TamsS60
recently had a chat with David Wood -- who has the rather fantastical-sounding title of "Catalyst and Futurist" at the Foundation -- and he's managed to set the record straight about how S60 as we know it will be phased out over the next few years to make way for a new (well, mostly new) development stack. Most notably, UI toolkit Qt will replace S60's legacy Avkon API around Symbian^4, which is expected to solidify in the latter half of 2010; this means that most current S60 applications will break except for low-level things that aren't using Avkon UI elements. That's a big deal and a bit of an issue considering the huge installed based of S60 users and apps -- but just like tearing off a bandage, it's gotta be done quickly and correctly for the health of the platform going forward.