This is the Andy Powell worry; we have made the repository too much of a "special thing" operating under "library rules". Make it more like Slideshare. I'm going to express this another way...
Think of the repository as place for permanent storage of a huge range of digital objects (research data, journals, cultural heritage material), which can then be accessed or delivered or analysed by a variety of different services which sit on top of of the repository (and not necessarily in the same place)
Then it's not so much the repository itself that needs Web2.0 but the range of the services which exploit that data.
My preference is talking with users about "resources" they care about. What tool do they primarily use to create their "primary resource" what other kinds of resource do they produce: "secondary resources", etc.
When talking with the powers that be in the college it is "digital library" or "digital archive", if they want further explanation on want a DL is, my explanation goes something like: made up of a piece of digital shelving software called a repository (and I throw the suppository joke first for a good laugh) plus a series of services that sit atop the shelving software that pull objects off the shelf which provides view or key services to the institution: bibliometrics, storefront window on R, T, L.
So yes this gets my vote, "repository" is a word that should be our own secret code word used amongst our small fray.