Microsoft is already warning users that "users of its calendar programs should view any appointments ... as suspect until they communicate with all meeting invitees.” Because daylight savings time is starting earlier and lasting longer beginning in 2007, many programs written prior to 2005 may not be equipped to automatically account for DST.
Y2K all over again? I hardly doubt it. But this does leave open the possibility that functions such as your payroll programs and clinical software could potentially record events on the wrong date if they occur over the midnight hour on March 11th and November 4th - a detail some are already worrying over.
Advice: Contact your payroll provider (ADP, Kronos, etc.) . They should be working on an update for the recently-found glitch. In the meantime, plan on scrutinizing your payrolls for these days. You should be anyways.
Clocks spring forward March 11th, 2007 and fall back again November 4th, 2007.
Wikipedia on DST.