So much for being undervalued. In the first trading session after Microsoft on Saturday withdrew its revised $47.5 billion offer, shares of Yahoo plunged 16 percent at the opening bell.

Microsoft recently upped its buyout offer to $33 per share from February's original offer of about $31 per share. But Yahoo rejected the latter offer, insisting that it was worth at least $37 per share.

Right now it's worth $24.56 per share, and analysts believe the pressure on Yahoo's board of directors and senior management will only increase as the company continues to grope for a survival strategy.

So is it really over? Well, as I noted in this recent post, both Yahoo and Microsoft are desperate for fresh strategies to help them avoid the pending threat of market irrelevance. Whether the deal would have provided what each company needs is a matter of speculation, but without the buyout both companies are right back where they were -- with no viable strategy going forward.

Should Yahoo's shares fail to rebound from today's fall, look for Microsoft to make another offer, perhaps after an upper-level uprising at Yahoo.