MS's strategy - to break Yahoo?
@stuart - good point... Microsoft can buy up the pieces that will be result of the collapse of Y! when the shareholders blow the board away having lost their chance at selling their stock at an overvalued price.
Since M would have massively changed Yahoo anyway, breaking it up, it's financially better for them to buy it already broken!
Whether Microsoft actually wanted to buy Y! at all is an interesting question - merely by offering to buy them and then walking away will hit confidence in Y! so badly that it gives MS a chance to overtake them.
From a personal perspective, I only care about the fortunes of Y! because I like the Zimbra mail system and MicroHoo would certainly have killed that dead.