Intellectual property, while not the same thing as copyright, tends to follow similar patterns.
In a single-owner project, the copyright is entirely theirs, and so is the IP. In a project with multiple contributors and no contributor agreement, the copyright is distributed: each contributor owns the copyright on any contributions he makes. The same applies to the intellectuals.
Lastly, in a project with multiple contributors and a contributor agreement, it depends entirely on the agreement. There may be a copyright transfer and/or a IP transfer clause, or there may be neither. It requires reading the license agreement to know.
Of course, it is also possible to assign the property rights to an entity instead of a person: I'm not sure whether you can simply assign them to the project, but it is certainly possible to create a skeleton company for the project and assign the rights to it. This way, no single person can direct what happens with the property, and no group of people can allow some to be used but not other stuff. Either the company's CEO directs, or the company's board directs.