I already 'ditched' 3.0.x
With that said, don't make the jump just because something is the new thing. There will probbly be less new hacks for 3.0.x as we get closer to gold but the 3.5 code base is not tested widely yet. Thats not to say the code has not been under heavy private and public testing, but it is still offered as 'unstable' meaning many will simply not download it to begin with.
So the ultimate answer is, you should make the jump once you think you're ready.