Many outlets are echoing a subscribers-only report in the Wall Street Journal that Yahoo's board has decided to reject
Microsoft's takeover offer. The NYTimes offers the only other independent reporting so far confirming this claim. The report says that Yahoo will formally reject the offer in a letter on Monday, since they believe it "massively undervalues" the company. Microsoft offered $31 per share, a 62% premium on the stock price at the time, for Yahoo; but the latter believes that no offer below $40 per share is tenable. The AP has some background on Yahoo's options
in responding to the bid.