I'm late to the show, but ....
I'm with osborn4 ... it depends on the graphic. I use centered A LOT, but have used left and right aligned if a strong visual element was in the text.
[stepping up on soapbox]
That being said, I was at a church this past weekend and noticed again one of my pet peeves. When a lyric goes over one line, PLEASE, PLEASE, PLEASE break the lyric where the MUSICAL break occurs.
For example ...
Hosanna! Hosanna! Hosanna in the
..... does not work from a musical point of view ...
Hosanna in the highest.
..... makes much better sense and is easier for the congregation to follow.
It is important that whoever is setting up lyrics either work with the worship leader or know the songs to know where the natural break in lyrics occur for long lines. All because a line is long enough to hold most of the words, it doesn't mean that it should!
[stepping down off soapbox]