Calculating a time in a time zone from multiple dates in SQL
First, let me restate your problem, to make sure I understand it correctly.  You want to take the NominalTime column, which is of type datetimeoffset, and replace the date part with today's date, where "today" is defined according to the timezone in which the SQL Server is running.  The time and timezone offset will remain unchanged, even across DST boundaries.

To roll one field of a datetime-like object forward or backward, use the DATEADD() function:

SELECT Id
     , NominalTime
     , SYSDATETIMEOFFSET() AS Now
     , DATEADD(day, DATEDIFF(day, NominalTime, SYSDATETIMEOFFSET()), NominalTime)
    FROM FaxQueue
    WHERE status = 0;


SQL Fiddle demonstration