I went the on-line Yum "preupdate" route.
The upgrade was painfully slow on a P4 (Northwood) 2GHz 32bit 2Mb system and took over 3 hours using
Comcast's High Speed Internet cable access.
After rebooting into F14, I saw that 161 updates were waiting and they took an additional hour.
Still, all seems to have gone OK. Crossing my fingers...
BTW, the default F14 boot-up splash screen looks like an Ubuntu delinquent threw a rock through my monitor's screen.
Best wishes and good luck to all.