Regardless this is fantastic news, it's been a many, many years since we've seen genuine competition in the OS market.

Really? I've been reading articles for YEARS about how Linux was Microsoft's biggest threat. Starting with those insane "Linux IPOs" in 1999/2000. And Microsoft pointed at Linux in the anti-trust trial. (ok, that was self-serving, but it ended up being true anyway). This isn't really anything new at this point. The numbers are just confirming it.