So I have received these new PIR but they are different than the one I had previously purchased.
I am not clear as to what what the wiring diagram is representing on the signal wire.
First thing is to look at the devices datasheet.
You can see that the chips output to pin 2 is via a resistor, so you should be able to connect Pin2 straight to your Ardunio, provided you are running the module from +5v.
If you are using a higher voltage to power it, eg 9v or 12v then you need to use a potential divider on its output to make the signal level suitable for the Ardunio.
ricky101:
If you are using a higher voltage to power it, eg 9v or 12v then you need to use a potential divider on its output to make the signal level suitable for the Ardunio.
No you need not. As you can also see the module has an on board 3,3V regulator 
But what's hard about them? They are as simple as you can get them? GND, V+ and a signal out. Just provide 5V to it and connect the output to an Arduino pin.
So I don't need to install a resistor to pull up the voltage like on the other one that I have?
Nope, output is just high or low.
So what is with all the crap that is shown on the right side of the image?
That's exactly what is says, it's a possible application of the module
the datasheet is clear: ground, output, power. but there is another picture that says: (+), (OUT), (-). this is confusing, why label a terminal negative if it is for ground? is this conventional? thanks.
GND is only a common name for a common reference point. A lot of times that's connected to the side of the power supply that's negative with respect to the other. So yeay, GND is a common name but some use - or 5V- (not to confuse with -5V) etc to point to the connection that needs to be negative with respect to the other. So names may differ, there is not a perfect standard for it.
GND most of the time is a clear name but that sounds weird if you somehow want to connect the GND/5V- of the module to the 10V of you're design and the 5V+ to the 15V of your design. The module still only sees 5V so is okay but the name GND may sound weird now.