@Victor - I don't think Yang said no to $33. Yang countered $33 by $37 and was probably expecting Ballmer to come back at $35. In fact Ballmer pulled a fast one on Yang and immediately pretended to walk out of the deal. He never tried to negotiate beyond the verbal offer of $33 without any details. You can't call this a mistake because even other big shareholders like Miller were expecting around ~$35 as a reward for holding YHOO for several years. MSFT played the same kind of trick again this weekend. They don't seem to have a sense of urgency or a sense of direction. In the process both MSFT and YHOO are getting weaker and GOOG is getting stronger every day. Not that there is anything wrong with it. :-)
Remember Terry Semel tried to buy facebook for 1B$ and then changed the price to 800M$ at the last moment. MSFT is trying to do the same with YHOO. But they fail to realize that Yang is not desperate and the GOOG boys are his buddies. So he won't stab them in the back, unless the MSFT offer is really really good...