This was proposed for PHP 5.5, but the vote failed to get the necessary 2/3 majority required to accept it into core, so it won't be implemented (despite the code to implement that change having been submitted).
It's entirely possible (with the plethora of new PHP engines and Hacklang currently appearing) that it will be resubmitted at a future time, especially if Hacklang decides to implement it; but for the moment the option of using C# getters/setters isn't available in PHP