"What's the timeframe and what do you promise to do if you lose your bet?"
It depends upon when the next new and shiny comes down the pike. One thing you guys can never seem to resist is new and shiny. Sometimes my Fedora predictions turn out to be correct. And sometimes they don't. To which one are you referring?
I'll sincerely give you credit, though. In general, the churning nightmare that is Fedora, after being vetted, tested, filtered, beta'd, properly QA'd and released by your parent organization, is absolutely top notch. Oh, RHEL's PulseAudio is nearly as bad as it was in Fedora, as I have already described. But it's easily removed. And packagekit inherits the perrenial locking problems that yum has had since the FC1 days. And it's still slower than Synaptic. (Although better than it used to be.) But other than that, RHEL and its clones are absolutely fantastic. I've taken a hiatus from Ubuntu on my home desktop, and am quite enjoying RHEL, CentOS, and SL. Especially SL, which is a new one for me.
Not that I ever left the RHEL family behind. It is a bitter-sweet combination of sadness and joy to me that several of my customers' venerable CentOS 4 servers must be upgraded in the next month. It's been a great 7 years of perfect OS stability. Some will be going CentOS 6.2. Others to Scientific Linux 6.1, or 6.2 if it is ready.
Oh, what the hell. I predict you'll be off systemd in 3 years or I'll buy you a burger. We can sync up in 2015. :-)