The default gtk setup shipped with previous RedHat releases have not been very good in the usability department, and IMHO this release would be a great opportunity to fix some of that (rather than waiting for GNOME 2.) Raleigh as a default theme, with the menu usability enhancements already in gtk 1.2.9, provides much superior widget recognition and overall usability to that found in previous RedHat releases.
with GTK+2.0 being the main source of work going on in that department we will probably wait on this (plus we are frozen on that for now). The Raleigh theme is a preview of what the default theme will look like once 2.0 is released.