But... what the heck. I know you're curious. And since the site that published this image originally has annoyingly watermarked it for some reason, I've created my own cleaner version:
This image conveniently does correspond with some information that's long been rumored. For example, Tango is widely seen as a way to bridge the gap with lower-end smart phones.
But how does this jive with what I've seen?
The documentation I've viewed, which highlights Microsoft's Windows Phone plans for the next six months, never mentions Tango or Apollo. It discusses various upcoming handsets from a variety of companies, as well as LTE compatibility in the first half of 2012, which belies the notion that Tango--supposedly due during this same time frame--is somehow only for low-end handsets. It's possible, of course, that Microsoft's LTE plans exist outside of the OS update schedule. Or that Tango doesn't even exist.
I'd also point out that competing at the low-end of the market only requires handset makers to lower prices. The Samsung Focus Flash, for example, is available now for just $50 and is a fine second-generation Windows Phone handset. This device blows away the years-old iPhone 3GS that AT&T is now selling for 99 cents (i.e. "free"), so it begs the question: What if an incredible device like the Focus Flash was simply subsidized for free? What a tremendous deal that would be. It's unclear how "Tango" improves on that. Assuming it's real.