Hi there. I've many computers running 6.1. The move to 01/01/00 went fine. The only thing that I saw so far is that 'uptime' reports a 1 day uptime at 00h00, and then a count of minutes starting at 00h00. For instance, if the computer has been started 10 days ago, at 00h15, 'uptime' will say '15 minutes'. Top(1) reports the same wrong uptime so I guess it is not uptime(1) that is wrong itself. However everything seems ok. I continue to test...
I cannot reproduce either the uptime or top problem on sparc or i386 ~6.1 (i.e. mostly upgraded to Raw Hide) Red Hat Linux.