This has been a problem here in Israel for a long time, causing me to once again think of our beloved country as some thirld-world one. No more! No the great US of A has accepted the regular annoyance of changing it's clock twice a year and the consequences of changing sceduled appointment times, etc.
Microsoft will release updates for Exchange 2003 SP2, Exchange 2007 will deal with this with no updates and the rest, well, one can hope PSS will provide workarounds.
More info here: