I am starting a project next week using Unity3D, I have known about this for a while and have poked around a bit to try and figure out how to do various things. I have been really impressed as to how fast you can get something done with what is basically a free product.
There are some superb videos on Unity3d Student which have been invaluable. I think I have got my head around the controls, UI, paradigms and scripting, although not all in one scene. As evidence of my work I have made three balls bounce around the screen, something akin to a carpenter making a door stop perhaps, but I am sure I will learn.