Microsoft - keep your filthy hands off Valve, leak shows MSFT would buy Valve
(www.gamingonlinux.com)
Obviously other people work there, that doesn't matter. What matters is who can make legal decisions about the company and I doubt that goes beyond Gabe. He's a greedy bastard who really only cares about money. He'd make less in the long run if MS bought them out but that doesn't mean the next person won't take the payout.
We've needed real alternatives to valve for a long time for this exact reason. They're already a monopoly. If they get bought out they'll abuse their status even more than they already have.