Marc Andreessen has a great blog post today laying out the possibilities in the Microsoft-Yahoo talks.  Unlike most posts on the subject, this one isn't trying to guess what might happen.  Instead, it lays out the options and the forces affecting those options.  What is a proxy battle?  How would it take place?  Who are the investors we're talking about?  What is a tender offer?  How is it affected by a poison pill?  If you are following the subject, check out his post.  It's a good primer for the rest of the pontificating on the subject.