The big humanities groups are sounding positive about this (quoting Andrew Mytelka in the Chronicle of Higher Ed, which lives behind a pay wall):
The National Humanities Alliance, an advocacy group, issued a statement this afternoon that greeted Mr. Leach’s nomination with “warm enthusiasm.” In a separate statement, Robert M. Berdahl, president of the Association of American Universities, expressed “strong support” for the nomination. And Pauline Yu, president of the American Council of Learned Societies, hailed the announcement as “great news!”There are some opportunities in this, I hope. First, any time you step into a job that was held by an ineffective person, you've got a shot to improve things, and Leach would follow Bruce Cole, a guy with a really big 'L' on his forehead. (And some people figure Lynne Cheney likes to jerk hard on that chokechain Cole wears.) Second, Leach was a founder of the Congressional Humanities Caucus, intended to protect the NEH from political attacks way back when.* So, Leach is a friend of the humanities, at least. Third, from what I know, he's somebody who has been concerned with process and ethics and that can't be bad.
It's a surprising choice: He's not a humanities person in the usual sense — best known for his work in international policy, I think. The only quote I've seen from him so far mentions 'history', not anything broader about the humanities. People do talk about him as 'scholarly', and in looking through stuff he's written, he does quote Yeats, too. Does that help?
This isn't the appointment some humanities people were expecting, but here's hoping that we'll see the NEH become a more viable agency.
* By the way, that's a bipartisan group, most recently urging (in a 'dear colleague' letter) not only increased overall funding but that NEH increase the amount of its funding that goes into peer-reviewed grants. At NSF, that's 26% of their funding; at NEH, only 16% (You can get the details on the NHA's website, here.)