It isn't really a "retirement." At the age of 95, he will remain chairman of the board and still plans to come to the company's Omaha HQ as much as he ever did.

But he has said he will be "going quiet ... sort of" and will leave all the decision making to the new CEO, Greg Abel, who has been serving as vice-chairman of non-insurance operations since 2018. Abel first joined Berkshire in 2000 when it closed its deal to take a controlling stake in MidAmerican Energy, where he was president.

Still, when Buffett announced at the May annual meeting that he planned to step down at the end of the year, he expected he could be helpful, especially if "we ran into periods of great opportunity or anything."

Becky Quick, CNBC's longtime Berkshire/Buffett correspondent, noted on Wednesday's "Squawk Box" that "for the most part" Abel has been running the non-insurance companies "for years now" and has done a "phenomenal job" at making sure things run smoothly and dealing with a lot of the problems that Buffett didn't want to handle himself.

She expects it will be helpful for Abel to have Buffett and his 30% voting control as a "fireshield to anybody who wants to come along and say that you're not Warren Buffett, this is not your company."

For several years already, Abel has been putting his own stamp on the way Berkshire manages its wholly owned subsidiaries.

Back in 2023, in a section of the newsletter with the headline, "Things are already beginning to change at Berkshire," we reported on a CNBC interview in Japan with Buffett and Abel.

While both men were smiling and almost playing it as a joke, it was clear Abel was much more involved in the management of the subsidiaries, in contrast to Buffett's famously decentralized hands-off approach.

At the 1999 annual meeting, Buffett and Munger said their "non-interference has enormous value, at least with the kind of managers and the kind of businesses that have joined us."

"Not only do people have more time to work on the productive things, but I think they probably actually appreciate the fact that they're left alone."

Twenty-four years later, Buffett said, "Our managers like autonomy, but they also get lonesome... I give them the autonomy, but Greg gives them both, and he gets somewhat more discipline out of the managers ... than I would get."

Earlier this month, Berkshire announced it was adding a new layer of management, appointing the CEO of its NetJets subsidiary to "support the outstanding CEOs of our 32 consumer products, service and retailing businesses, and uphold Berkshire's culture and values."

But while Berkshire is beginning to change, it won't be a dramatic overnight shift.

As shareholder Ann Winblad told CNBC's "The Exchange" Wednesday, while the company will "operate differently" with a new CEO it won't "fundamentally change in its strategies."

Andrew Bary at Barron's writes Buffett's continued presence at the company "could mean that important matters such as a potential dividend [which Buffett has consistently opposed], stock buybacks, and the deployment of Berkshire's cash balance of more than $350 billion could remain unresolved for some time, perhaps until after Buffett's death."

Over the very long run, however, it will be difficult for Berkshire to avoid becoming more like other corporations that don't have Buffett's spectacular success to shield management from impatient investors who are likely to push the company to abandon his insistence on waiting for the right opportunities and resisting the typical C-suite compulsion to justify its existence by constantly doing "something."