Derick himself admits that its probably not the best approach:

The patch is most likely not the best way of implementing this either, and I am also not sure if this patch should be applied to PHP's CVS at all.

He offers the following as an example of how this would be used:

function foo2( integer $i, float $f, bool $b ) { }
foo2( 'string', 42, 49.9 );

The example above should show:

Catchable fatal error: Argument 1 passed to foo2() must be of type integer, string given, called in /tmp/test.php on line 16 and defined in /tmp/test.php on line 12

Derick also posted his Database Design Slides from his talk earlier this year at php|architects php|tek