From Wired:

The Redmond, Wash.-based software maker upped its offer beyond the original value of $44.6 billion, or $31 per share, according to a person familiar with the matter. The specifics of the new offer weren't known by this person, who didn't want to be identified because the negotiations are still confidential...

...The talks were expected to continue into the weekend.

Microsoft ups Yahoo offer above $31 per share [news.wired.com]

Added:

In a comments to Microsoft employees Thursday, Ballmer said he has a price in mind but didn't reveal it.

"I know exactly what I think Yahoo is worth to me, exactly," Ballmer told the employees, according to a transcript filed with the Securities and Exchange Commission. "I won't go a dime above, and I will go to what I think it's worth if that gets the deal done."

So the floor is still open for Yahoo to come back with another price, and if it's within Ballmer's limit, it's all over but the shouting.

[edited by: Marcia at 10:48 pm (utc) on May 3, 2008]