Disagree. They've been losing relevance for a long time, and we're noticing now that they're struggling to find any relevance. They did have a lot of relevance to lose, as they squandered away what relevance Windows had, trying for markets they were weak in (server) while neglecting markets they were strong in (desktop), all while continuing to be so far behind the curve they just don't get what's going on until it's years too late (mobile).
They might have been a strong player in the game console market, but then they pulled an XBone.
Business is still pretty big, but with Windows losing day-to-day familiarity with users, their last bastion is going to erode quickly as users start asking "why can't we use something else?" I fully expect them to throw billions at trying to find relevance for years to come, though. This all might be foreshadowed by RIM and Blackberry: originally king at business, trying to fit in elsewhere, disrupted by technology they didn't grasp, falling behind, throwing money at trying to stay relevant, while everyone else wants to move on.