@jobalicious - the future of wordpress.org would basically depend on what got included in the deal. Obviously Microsoft can't buy the wordpress software, but they can buy the site where it lives.The wordpress.org domain is not currently owned by either Automattic or the Wordpress Foundation: it belongs to Matt personally. This gives him the choice, when the time comes, between selling it off along with Automattic or handing it over to the non-profit foundation which currently owns the trademark. (Microsoft could probably manage without the trademark, if they had to, and might even prefer to rebrand.)

If the wordpress.org site was acquired along with Automattic, the official software would probably limp on for a while, but the main focus would be on encouraging people to move their content and personal data to wordpress.com instead. Obviously the community would fork the project in response, but there's no telling which, if any, of the forks would survive.