The following outputted "Bias" does not appear to take into account Daylight Savings Time when executed on SQL 2008. The simplicity of the code is great, but it doesn't appear to get the current Bias. I changed the clock on my machine, restarted SQL Server, but I did not reboot my machine when I tested.
DECLARE @TZIBias int
'SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Pacific Standard Time',