There are some rules as to what software there is, however. For instance, we won't replace any package that comes with the distribution. One of the complaints that we frequently get is that the world of RHEL is very old and outdated - EPEL will do nothing to assist there, we will simply add on to the existing distribution with what we can. If a package requires something newer than comes with the version of RHEL that we are targeting, then we cannot ship that piece of software. It's better to have less software than to break existing systems in new and exciting ways :).
With some exciting recent changes, Fedora contributors can now contribute to EPEL easier than ever before! Thanks to some new capabilities in koji, the Fedora buildsystem, we can now build EPEL packages right from within the familiar interface of koji. Updates are issued via bodhi, so again, the same workflow that you use for Fedora is now available for EPEL, rather than some arcane buildsystem called plague (working with it made you want to get rid of it like the plague!)
That's all well and good from the contributor side, what does this mean for users of EPEL? Simple - due to the new changes, hopefully more contributors will be interested in EPEL, and therefore the range of software available will grow wider and more varied.
If an enterprise is packaging free software for their internal use, why not share that work with others in order to avoid having them go through the same effort? Also, by compliance to the Fedora packaging guidelines, you're ensured high quality packaging of that software that you consume, rather than haphazard packaging by unknown people. Moreover, the burden of maintenance is shared with an entire community of people, rather than simply being confined to a single person in a single organization.