Suggesting that Ubuntu neglects alternatives would be going too far. Still, it does seem accurate to say that the latest Ubuntu release focuses on its version of GNOME, and treats other desktops as secondary, particularly if they are not developed in a separate sub-project.
Despite Ubuntu's emphasis on usability, in the end, the latest versions of Fedora and Ubuntu remain based on GNOME and generally offer comparable user experiences. In the few places where one of them does not, modifications remain easy, except where Ubuntu has unilaterally altered GNOME.
All the same, a comparison of the two shows a clear picture of policy. Focused on reaching profitability and increasing usability, Ubuntu seems more centralized in its policy than Fedora.
By contrast, Fedora seems to retain more of the spirit of a traditional distribution, shipping a distribution that does not venture far technically from what upstream projects like GNOME offer. Nor does Fedora show many signs of preferring one interface over another, aside from the fact that it defaults to GNOME.
The difference can be seen in the release notes. On the one hand, Maverick's release notes are largely a list of new features and known problems, with usability issues and interface notes at the top, and the alternative interfaces to GNOME each placed in their own brief sections.
On the other hand, Fedora 14's release notes are divided by types of users, with sections for desktop users, system administrators, developers, and other specific audiences, such as amateur radio and musicians, and alternative interfaces placed where everyone can read them.
The message in the release notes is that Fedora is for all sorts of users, whereas Ubuntu seems focused on as straightforward an experience for new users as possible. Nothing could more indicative of the differences in the two distro's current concerns.
Which of these two approaches to distribution-building is preferable remains a matter of choice. Ubuntu's popularity and the speed of its changes suggest that there is something to be said for its commercial, centralized approach. Yet, at the same time, Fedora's more generalist approach seems more tolerant of the differences in how users work.
In the end, neither Ubuntu 10.10 or Fedora 14 are major releases. However, if you look closely, you can see the seeds of differences that might grow larger over the next few years.