I have asked Microsoft this in webcasts, and posted on this site as well... and not surprisingly, I have not received any official response. Maybe I will have better luck here:
For those of us who have Exchange Servers in the US, but have customers located outside the US, what specific time zones do we need to run the Exchange Update tool against. In last Friday's webcast they mentioned that you didn't need to run the Exchange tool against any "non-affected" TZ's, but then didn't give guidance as to what specifically those were. They stated that some 40+ TZ's made adjustments, but we are unsure if that means we need to run the Exchange Tool against those as well... and if so, what are they?