Is it worth to get Unity 3.x now, with Unity 4 near launch?

I wish to get the free version, by the way. It’s not about paying; it’s just that I’m worried that Unity 4 will be too different and that anything that I might learn to do using Unity 3.x will go to waste.

You can download the free beta of 4 and start learning with that. You can also download 3.5 and upgrade when 4 is released - I just upgraded to Unity 4 free beta and kept working on existing projects without noticing any difference in workflow or features. It’s the same platform, the same editor and the same scripting API.