No disrespect taken, petey, I suppose it's a fair enough question, and I appreciate your active participation in the conversation. The article wasn't necessarily meant to be legacy-defining, though. ;)
Benjamin Disraeli is alleged (by Mark Twain, rather apocryphally) to have said, "There are three kinds of lies: lies, damned lies, and statistics."
Regardless of the phrase's true authorship, I generally agree with its commentary; numbers are used all the time to mislead. As you rightly suggested, it's not an issue of life or death in this case, but the point remains: A lot of statistics get simplified, especially when companies use them for marketing purposes. Granted, Microsoft revealed the 200M figure in fairly low-key fashion this time-- but they (like most big companies) have been guilty before of trying to pass off creative accounting as legitimate financial successes.
Some customers are appropriately skeptical of these statistics, but others not only accept them, but also use them to make purchase decisions, or to otherwise inform their opinions about a certain product or company. As a result, I find it useful to examine provocative statistics from multiple angles, and to encourage a healthy conversation (like we are fortunate enough to have here) about what the numbers actually mean. To some people, 200 million sounds unequivocally impressive under all circumstances. But this is demonstrably not the case; the value of a number is usually, if not always, contextual. What is the appropriate context in this case? Well, that's what I attempted to answer with the article.
Also, if recent InformationWeek comments threads have shown everything, it's that our readers are passionately divided about whether Windows 8 is any good, and whether tablets are really surpassing PCs in relevance. It's fun water cooler discussion, and this article was intended to tap into this vein. If people are going to have "Mac vs. PC" or "Windows 8 vs. Windows 7" or "tablet vs. laptop vs. hybrid" arguments anyway, I hope articles like this one can enrich the debate!
Also, just to make sure I wasn't understood (per #3 in your mesage), the point was not that Microsoft is dying. Outside of Windows, most of the company is actually doing really well. But Windows has been a traditional cornerstone of the company. I don't think Windows is going to die, per se, but it's changing in relevance, which means the whole company's emphasis is changing. I think this is relevant to many people who use Microsoft products, especially those with investments that will be impacted by the company's future strategies.