Sorry if this is a silly and/or stupid question but... Will there ever be, or would it even be possible to have a PHP.NET? Or have I got the wrong end of the stick?
The two are totally different, they are in competition with each other. Both will try to be good at their ends. So i dont think there is going to be anything as such in the future. However, you can use PHP inside of Visual Studio, there are plugins available for that.