It's possible that Microsoft will be lured back to the negotiating table with Yahoo, although this time discussions may centre around a stake in the company rather than an outright acquisition. 

When talks to acquire the Web company fell apart earlier this month over an inability to compromise on a purchase price, many shareholders expressed disappointment.
They gained an unexpected ally in Carl Icahn, who bought up more than 50-million Yahoo shares and nominated a new board ahead of July's shaerholder's meeting.
Icahn is also seeking SEC approval to buy still more shares, to control up to 7% of Yahoo.
Icahn hopes to force Yahoo back to the negotiating table but, up until now, there was no reason to believe that Microsoft would wish to re-open talks.
The new approach could be more palatable for the current board, who may be more willing to talk in the face of a looming proxy battle.