Ubuntu's response to this dilemma has always been interesting, and sometimes painful to watch. Rather than refer openly to proprietary or even non-free drivers or applications, it has preferred to call them "extras" or "restricted" software, obscuring their nature. But, by whatever name, it has seemed unsure what to do with them. On the one hand, Ubuntu developer Matthew Garrett condemned Automatix, a tool for providing proprietary elements as "dangerous" (and probably he was right). Yet, on the other hand, a few releases ago, Ubuntu was under fire for the indiscriminate inclusion of non-free wireless drivers.
Ubuntu has also tried to address the issue with Gobuntu, a variant that included only free software. Then, a few weeks ago, Canonical founder Mark Shuttleworth suggested that, given the relative lack of interest in Gobuntu, the Ubuntu family might be better served by shutting down Gobuntu and supporting GNewSense, an Ubuntu-derivative with the same aims that is somewhat farther along in its goals.
In the last couple of releases, Ubuntu has wobbled in much the same way. The previous release or two provided a Restricted Drivers Manager in the Systems menu for loading proprietary elements -- although with such vague language that new users must have been puzzled. When you logged in for the first time, a popup message would mention that proprietary drivers were available. Now, in Hardy Heron, the name has been further obscured to the Hardware Drivers Manager, and the popup message no longer appears, leaving users to their proprietary pieces in the graphical package manager.
Aside from drivers for ATI and NVidia graphics cards, most of this material can be found the Ubuntu Restricted Extras package, which includes such elements as a Flash plugin, Java, Microsoft Core fonts and MP3 codecs, and is faintly reminiscent of Automatix. At the same time, you can also choose to enable Gnash, the free Flash replacement, assuming you know enough to look for it.
Should you choose, you can also install WINE to run Windows applications under GNU/Linux, in which case its configuration tool is placed prominently in the top-level of the main menu. Then, just to complicate matters, the Add/Remove Software tool includes a filter for a third party -- read "commercial," and therefore, most likely, proprietary -- software, although the repository is not enabled by default and currently contains nothing.
In short, Hardy Heron does not mark any decision on where Ubuntu stands on the issue of including proprietary elements. If you are unkind, you might say that Ubuntu is still waffling and trying to have it both ways, either hiding or excluding the non-free from the default install, but making it readily available for those in the know. If you are more generous, you might say that Ubuntu is in a classic double-bind, under pressure to adhere to free software standards by the community, yet unable to find a compromise that will satisfy everyone so long as commercialization remains a goal. One of the results is that Ubuntu seems to be spending an inordinate amount of time on the problem, but, under the present conditions, that seems unavoidable.
There are plenty of additional minor enhancements -- unsurprising, given that Hardy Heron is one of the periodic releases for which three-year support is promised -- but most of them are only of interest if they help you to enable your particular hardware. In general, Ubuntu 8.04 is a release that consolidates existing tendencies rather than introduces revolutionary changes, a fact that makes the hype heaped upon it seem all the more inappropriate.
Ubuntu, like any of dozens of other distributions, has been ready for the desktop for some years. Hardy Heron simply makes it incrementally more so, while still not resolving the essentially unresolvable debate of how to make free and proprietary elements co-exist. It's a debate that is far from unique to Ubuntu, but one whose ambiguities seem to be stronger with every release of that distribution.