What do we call this Microsoft-Yahoo thing, anyway? "Merger"? "Buyout"? "Elaborate game of footsie"? It's not a hostile takeover — yet. But Steven Davidoff writes in DealBook that Microsoft could go hostile if Yahoo resists. Microsoft CEO Steve Ballmer wrote:

Depending on the nature of your response, Microsoft reserves the right to pursue all necessary steps to ensure that Yahoo!'s shareholders are provided with the opportunity to realize the value inherent in our proposal.

If Yahoo's board of directors balks, Microsoft has a narrow window — mid-February to mid-March — to launch a proxy contest and unseat Yahoo's board. Until then, it's not a hostile deal. Let's just call it a "surly takeover" instead.