If you're looking at it from a getting-a-job perspective, I'd definitely at least learn 2.x as well. The code I work on is still targeting python 2.4 and to the best of my knowledge there is no plans to move to even 2.6, let alone 3.0 in the near future. There will be a ton of 2.x python code floating around for years to come and the vast majority of python jobs will involve working with that code.
So I'd start by learning python 2.6 while the whole time keeping an eye on 3.0 so that you are at least aware of what bits of your 2.x code won't work in 3.0
