Anyway, I think any discussion of modules really depends on the nature of the language. How are people likely to compose their programs? Erlang programs can be updated on the fly. Arc programmers tend not to treat libraries as black boxes. As for me personally, I like to generate my programs by writing other programs. Sometimes a separation of modules is useful so that some can be autocompleted in an IDE or separately compiled. There's a wide range of crazy spins on collaborative (and otherwise modular) programming which might provoke different ideas of the term "module."
In the end, modules are the abstraction (or lack thereof) associated with individual programs in a community. Even very pure languages can have pretty flaky abstractions at that level thanks to the soft, changing factors of just what the community is, what it wants to be, and what tools it uses to program and communicate. I generally know what I like in a module system, but talking about "Do we need modules?" probably isn't as useful as talking about particular module-level characteristics like searchability, hackability, documentation, and centralization (in the sense of everyone contributing to the same project).
