It's actually Symbian ^4 that will be the big Symbian Foundation release. Symbian ^3 is sort of "half-way-point", bit like Maemo 5 is the last step before Maemo 6.

As for which one is better? I don't think that's really important question. Nokia* is developing both for different purposes. Hopefully both wll be very good for what they intended for.






*In reality Nokia does the vasy majority and dominates Symbian development, despite what Symbian Foundation and Nokia says about coperation in Symbian development