Not to put too fine a point on it, but yeah, we’re talking about the iPod touch model: It’s about platforms. That run apps. That people can develop awesome little programs for. In other words, a good PMP won’t just have great codec support and be able to push HD video, it’ll get you on Twitter or Facebook or tell you what’s good to eat nearby.

Not convinced? Check out the new Archos 5, which dumps the old OS for Android. Or the Creative Zii, also allegedly launching with Android. If you’re in the second tier, grabbing a popular app-friendly platform is not a bad way to compete.

Apple itself noted that old-school iPods were on a death march—so the company added a video camera to the nano, to keep it alive for a generation or two more. True, Sony’s X-Series appears to be keeping on keeping on, but it feels like an anachronism, albeit with a nice screen—no extendibility, and a horrible internet browser.

The argument really comes down to the Zune HD, launching this week. It finds itself in an awkward position, essentially because of the effective limbo Microsoft’s mobile OS is in—in other words you can’t easily develop apps for both Zune HD and Windows Mobile, which Zune’s Brian Seitz basically admitted to the Seattle Times: “What we didn’t want to do was build two parallel app store experiences that didn’t work together.”

So there’s no open app store, but in the meantime, Microsoft’s providing the apps with a handful of chosen developers, so we’re stuck with games, and soon a Twitter and Facebook app. But what is clear is that Zune is a platform that people can develop for. And it seems inevitable that’ll be common with the next version of Windows Mobile, or the mysterious project Pink, if that is something else—at least, if Microsoft’s actually serious about the Zune having a future.

In other words, it’s startlingly clear now that the traditional PMP is history, replaced by PMPs powered by mobile platforms. They’re smartphones without the “phone,” and even lacking that major element, they’re surprisingly valuable, more pocket computer—with internet and apps—than glorified video player.

From the patent, we can see that the Zii is a wi-fi-equipped touchscreen media player, fitted with an “HD” camera, Bluetooth, and, well, that’s about all we know. The presence of a developer version, called the Zii Egg, seems to promise some kind of app support, though it’d be a mistake to immediately jump to the conclusion that the Zii will therefore have an app store; it could just be a dev platform for third parties who could be developing stock apps for the device.

Oooooooor, as Engadget plausibly suggests, this could be a part of the first wave of Android PMPs, which would, like any Android phone, have root-access developer units. In that case, Creative has what could be an interesting product: a touchscreen, connected PMP with a decent camera and a worthwhile app store, making it a more direct competitor to the iPod Touch than we’ve ever seen before. For now, though, questions! Like what was up with the strange language in your “Zii Stemcell” announcement, and how closely are these two things connected? In due time, I guess. In due time. [FCC via Engadget]