Is Yahoo twice its value now?

Barron's is bringing a very good point. While Google is suffering of concerns on the online advertising market, real concerns or just seasonal panics, Yahoo! is under the shelter of Microsoft offer at $31 a share. If Sir Microsoft was not here, Yahoo!, following the same trend, would be in the $15 range...

So, is Microsoft missing a great discount deal here? can they send some mixed message like a market adjustment, saying they are ready to pay a premium of a couple of percent and thus, at a revised valuation their new offer is now at $20 a share? after all, it's just a $14B adjustment... why not give it a shot?