Strange and mysterious Linux crash

So my Linux box just locked up. I was running VMWare, AIM, Konq, KMail,
and quite a few Konsole sessions. I couldn't kill X. So, I grudgingly
rebooted, but I got a message about a kernel panic and not finding init.
Odd. So I booted from a floppy and mounted my filesystem. Here's what I
found:

/bin, /lib, and /opt are no longer directories. /bin is now a copy of my
passwd file. /lib is now a copy of my group file. And /opt is another
copy of my passwd file. /usr/local/lib is now a copy of something that
looks like a sound config file, with entries like "synth:64:64:R" and
"pcm:64:64:P".

SoooooooOOOOooOOOOoOOOoo... what the heck happened? Any guesses?
Thanks,
~M