The Koch brothers have been fighting to take control of the Cato Institute, against the wishes of its current leaders and staff, who they deem insufficiently devoted to the cause of plutocracy and the Republican Party. After a lengthy, public fight, the two sides reached a compromise, in which CEO Ed Crane will be pushed out and John Allison will take charge of the libertarian think tank. Allison is the former chairman of BB&T bank and best known for donating vast sums to universities and using his leverage to force them to assign their students to read Ayn Rand screeds. The running of a libertarian think tank seems like a more appropriate venue for Allison to act upon his devotion to Rand's nuttery than forcing it upon students who are trying to learn actual stuff.
Allison's ascension is in keeping with the general trend of the Washington libertarian movement to define itself mainly in economic terms. (The trend has been opposed by a handful of libertarian dissidents, the most prominent of whom have been purged.)
It's not just economic libertarianism in general that moves the likes of Allison, but a specific belief that economic freedom is defined primarily as opposition to egalitarianism. (As opposed to focusing on something like the regulatory power of state and local business cartels.) Allison has called egalitarianism "the most destructive principle in our society." The general thrust of Rand-influenced libertarianism, which you see in the philosophy of Rand-influenced Republicans like Grover Norquist and Paul Ryan, is that the central evil in public life is the poor using the political system to gang up on the rich and redistribute their resources. (For those unfamiliar with my thoughts on Rand and her influence on the contemporary right, you can read them here.)
Allison will no doubt continue to support Cato's libertarian work on foreign policy and social issues, but expect Cato's central thrust as an anti-egalitarian organization to continue or intensify. And since this places Cato in support of the Republican Party, it will probably satisfy the Kochs.