Heh. If we wait for enterprise distros to do anything, Linux slows to a crawl. It's not as if enterprise guys don't go through their own cycle of configuration testing and ship kernel.org kernels unchanged and untested.
The big point in favor of changing the default in kernel.org (after more a year upstream in kernel.org, I'll note) is just how terrible PFIFO_FAST turns out to be as shown by Toke's CDF plot in that blog entry and all the other measurements we've made. We're orders of magnitude from where we know we can be. The improvement is *not* subtle.
But changing a default *is* a serious step, and until we get everyone in a room to talk it through, expressing all the pros and cons and concerns, it's not a decision to be taken lightly.