All I know is quad means four, and it has four. Just because two are different doesn't mean there's not four. You could code smaller applications like an internet radio player to use the M4s, and then it wouldn't take any processing power from the rest of the device.
But by that logic the Pandora has at least a tri core processor, just count the DSP and the graphic chip too. And the Pyra has it's two real processor cores, two little co-processors, two graphics units PowerVR SGX544MP (because meaningless numbers and letters are fun), the TI 2D BitBlt graphics accelerator and the DSP, so it's octa core. Yay!11!
The problem with your example is the following: Sure, you can code an internet radio player to run on it. But it will take you huge amounts of time and you'll need to be a more advanced coder than the average great guy who is porting apps to the Pandora. You'll need to figure out access conflicts to the network chips (3G/W-LAN), to disk, to the audio output, you'll need to learn how to make your code run on the M4s at all (not as easy as it sounds, most likely), then you'll need to actually code the app, and I'm pretty sure you'll have a lot of trouble because you can neither run Linux on them (even more trouble sharing hardware components) nor access certain nice features the kernel usually provides to you, because it's running separately on another piece of the die. So you would need to code it in a very low-level fashion, which is again difficult and a huge lot of work. There is no drop in web radio player for M4s (neither are a lot of other applications, if any. Probably none).
Then, when you are finished, those M4s run a 200Mhz max. That means the task of playing a web radio station isn't such an easy task anymore, it will have to work much more than the full featured cores would have to. That means the full cores might even use less energy for the task because they could sleep (i.e. powersave) for 90% of the time while the M4s need to work for at least 70% of the time.
It's probably simply not worth the effort. They are made for other things, for example you could probably dedicate a portion of the GPIO pins to them and use them to control a machine. Say, a stepper motor driver. Or read a sensor array. Then you would work out a simple protocol for sending data for the M4s, you wouldn't need to share any hardware between them (maybe give them some RAM, but not much for a simple task) and they would just provide you with a simpler way to retrieve/send data which has already been preprocessed/will automatically get some low level processing applied to it and not have to do it in real time, you have a little buffer.
Very useful in industrial/automotive applications. Not in the Pyra.
And even in such contexts, you don't call them processor cores, but coprocessors.
Look in Wikipedia, it lists the OMAP5 as consisting of two dual core processors. That's much more appropriate.
Calling the OMAP5 quad core is severly misleading. If you don't understand the subtleties, then just believe me or ask someone else for confirmation and then believe that person, like Exophase or notaz. WizardStan has already posted a similar opinion to mine.
I might have gotten some little things wrong, people like Exophase or notaz could probably explain it better and more accurately, but the overall picture is right.
Edit: Or maybe look at it like that: M4 processors are also sold separately. When they are sold like that, they are called "micro controller" and used in products similar to the Arduino (which I hope you know, otherwise you don't need to read on the comparison). Do you really think if you slapped the guts of an Arduino onto the Pyra board that should be considered Penta core because it's A15*2 + M4*2 + Arduino microcontroller?
But you forgot to also tell the "Bits" of the OMAP5, like the old "Console Classification" 8, 16, 32, 64, 128... where do we actualy stand right now after that classification? ^_^
