Since version 2.49 Blender has gradually improved . . . except that it sometimes loses features.
For a while there was no Knife tool but it is now back as of 2.65.
I never thought of Projection Painting as a "feature" though - more like an essential element - but it does not seem to be there any more.
I posted on BlenderArtists Forum asking for any help on how to use Projection paint in 2.6x versions and received zero replies.
There does not seem to be any tutorials for it and the 2.6 wiki is mostly empty: how the Blender lords expect anyone to use their software is a mystery to me.
What is Projection Paint? think of it as being able to paint a photo flat on the side of your model.
It really is very useful and can't be replaced easily by another method.
I'm not happy. Blender has been my preferred modeller but this is the first time I have run into a serious feature fail.