So, what's a poor marketing schmuck to do? One tactic we use regularly is to find out early on who all of the key player in a project will be and get a broad sense of their roles. And when I say broad, I mean really, really broad -- as in, there are only three major roles that are relevant to the success of a project and a single person/department can potentially occupy more than one of those roles.
The roles are: helper, resource, judge. That's it. A helper is someone whose job it is to make sure the project gets finished. A resource is someone who controls some asset that the project needs in order to get finished. A judge is someone who has veto power over a particular part of the project or multiple parts/the whole thing.
Once you know who the players are and what role they'll play, you can begin to make note of the 'limits' of their power. For example, say your helper (usually your client within the institution) is in the Admissions Department. He or she has power over large swaths of what happens in admissions, but may have no power over anything that happens in IT.
Alternatively, say you need photos taken for a project and rather than budget $8K for a photoshoot you accept the offer of, "Hey! So-and-so in marketing can do the photos!" Now So-and-so is a resource.
Once you have an overview of the role everyone will play and you know how far their influence extends, you'll be able to plan for different project phases appropriately -- and include/drop features based not only on their value to the project, but also on the extent that their ultimate adoption or deployment represents a threat to the project's completion.
