Jonathan Dresner’s comment about computer and information technology as still another growth area in university administration deserves to be foregrounded:
Another area that has seen substantial administrative growth at institutions I'm familiar with is technology management. At one college, computer services were initially a suboffice of the library. When I was there the tail swallowed the dog, and the library became a coequal branch of Information/Technology Services, and the former head of computer services now outranked the library director. Distance learning often has its own directorship (especially at a land-grant institution with far-flung and rural constituencies), purely managerial (there's no curricular director for distance learning, that's departmental).
Obviously technology administration has found different niches in the org chart at different institutions. In the 1980s Clemson adopted the model of librarians as faculty that prevails at a lot of universities. This made the Library a sort of 6th College (albeit a very small one), and its top administrator a Dean (a dean who has been at a chronic disadvantage competing for funds with the deans of the 5 academic colleges). Meanwhile, the Department of Computing and Information Technology was put in a separate area reporting to the Provost, so its top administrator carries the title Vice-Provost.
In any event, Computing and Information Technology at Clemson has three levels of administrators, many of whom are officially titled"Lecturer" to exploit a loophole in the South Carolina civil service categories. (Counting these"Lecturers" as though they spend time in the classroom or the lab is one way that Clemson inflates its faculty totals in most public reports.) Meanwhile programmers are always leaving DCIT because their jobs are in the regular civil service categories and their state-mandated salary range is grossly uncompetitive with the pay they could pull down in the private sector.
Clemson also has a central office for distance education. It’s part of Computing and Information Technology now, but started out in a different part of the organization. So far as I can determine, putting a central office in charge has meant that far fewer courses are being offered online or on video that would otherwise be the case. The suite of committee approvals and managerial signoffs that academic departments have to go through to offer a"distance" version of one of their existing courses is truly formidable.