1) Optimizing for P4 is ... messy
2) If you're using C2D, etc., you can already use the 64-bit distro.
So why not
stay with generic, where most users would benefit.
Sure I could use 64-bit, as could all the others using 32-bit on
64-bit capable CPUs (I guess 50% of all fedora-x86 users).
- Clemens