Could be the whole SMP-gone-mainstream thing... ;)
The x86 architecture has gone through some interesting permutations since 2001.
*sigh* I remember kernel 2.4.4... Wrestling with going from Slink to Potato and ReiserFS in 2.4.6 going haywire... The install discs still have a warm place in my big CD binder of Linux CDs going back to The Linux System Administrator's Survival Guide's Slackware 3.0 pack-in from 1996.
We've come so far. B-tree filesystems (B+TRee now) are hip again, gentoo's visibly early console/splash work has paved the way for xsplash, 1.6ghz chips have become a hot item again, and we're finally at the point where 256GB SSDs are competing with the 250GB Hard Drives everyone was awestruck with years ago. Good times.