I have absolutely no idea how big, small or non a problem this is, but from /tmp/install.log after an install of Winston: ... Installing gnome-libs. group utmp does not exist - using root ... No clue what this is about. Sorry.
/usr/sbin/gnome-pty-helper is sgid utmp on a RH 6.2 install which gives it permissions to write to the utmp file. Not having a group utmp makes it impossible for GNOME based programs which use gnome-pty-helper (eg gnome-terminal) to update utmp information as to the user login.
Basically, the package needs to prereq whichever package creates the group (either utempter or initscripts, IIRC.)
Not seeing this error on beta2, although the package doesn't prereq utempter (which does create the group).
also not seeing this in beta3, so closing the bug