In reply to The Lemming:
> Does what it says on the tin.
> I'm preferably interested in Nikon and the cheaper end of the spectrum.
> I have a D5000 but it does not always focus well
If you want to video stuff with autofocus and are looking for a new camera to do this then there are better options than a DSLR.
A DSLR is great for getting a 'film effect' with the potential for shallow dof etc, but manual focus and static or sliding shots bring the best results.
I have used a D5100 and have had very pleasing results when filming. Never used autofocus whilst doing it though.