After devoting his time, energy and brain power to giving away his money through the Bill and Melinda Gates Foundation, he's not likely to return to an active role at Microsoft, said Lance Ulanoff, editor in chief of tech news site Mashable.
"He'll always have an influence, but I think he loves philanthropy too much," Ulanoff said. "Plus, he's supposed to be pretty much divested by 2018."
Gates plans to sell about 80 million shares per year to help fund his charitable trust until his financial stake in the company is eliminated.
"Investors don't want him back. Actually there was a bunch of investors that were calling for him to step down as chairman," Ulanoff noted.
(Read more: Time for Gates to go, say top Microsoft investors)
But whoever ends up taking the reins at Microsoft is going to have his work cut out for him, according to TechCrunch East Coast Editor John Biggs.
He says Ballmer is leaving a mess for somebody new to clean up and the company simply isn't coming up with anything new product-wise.
(Read more: Microsoft's Ballmer gets less than 'A' grade in pay)
"They're just making a bunch of me-too products that are coming out too late," Biggs said.
—By CNBC's Althea Chang.