Get the latest KDE in otherwise stable Fedora
By a thing on 31 May 2008
yum update 'kde*' soprano 'extragear*' --enablerepo=rawhide
Despite the version still beginning with "4.0", it is 4.1 Beta 1.
You might want to make a daily cron job to run this.
Thanks to a Dot KDE post for the information.