One of the features included in the PHP 5.x releases is type hinting for validating that you have the right values for your functions and methods coming in. In this new post to his blog Ilia Alshanetshy takes a look at the the feature and gives a patch to add it .
On a general level most people agree it would be a good idea to have, since it is an optional feature and does not introduce any regressions, heck you can even mix type hinted code with the non-type hinted one. The "PROBLEM" has always been combining of PHP's typeless nature with type hinting, which is where the consensus has been difficult (impossible) to reach.
He mentions an example of why its such an issue (technically, both 1 and "1" are valid numbers) and includes a link to a patch that gives a new hint to help with the problem.