So let's say you have a CS background and want to pick up python today - is it worth it to read up on the 2.0 stuff or just go right for 3.0 seeing as 3.0 is "backwards incompatible"? Is there a mass exodus to 3.0 happening or are there going to be a lot of people (e.g. researchers in other disciplines whose life is only peripherally programming) who are going to stick with the 2.0 that they already know and love?

And is this (http://docs.python.org/3.0/) the best place to look for 3.0 learning material or is it better to do the Dive Into Python (for v2.0) thing then figure out the 3.0 differences?