He has been ruled out for personal reasons which cannot be revealed at the moment.

I was over-ruled by the judge,

He has not been ruled out of the entire tour but is going to miss the first Test and is returning home.

Vaughan is ruled out. He is going home.

He [Vaughan] is ruled out of this Test, but is not out of the series at this stage. Vaughan is to return home for treatment. It is too early to say whether he will be fit for the remaining two Tests and the one-day series.

Vaughan is going home. It's too early to say whether he is ruled out of the series altogether.