July 8, 2013: The International Union has a thorough summary of the new DOT regulations now in effect. While much of this will impact nonunion operators and drivers more than union, a few parts are very relevant to many drivers.
Examples of important things to note are the prohibition on the use of hand-held phones (page 15 in the summary); the prohibition on more than eight hours of consecutive driving (page 11), which now outlaws for example a UPS package car driver or cartage driver working all day and then taking their lunch as the end, to get off earlier.
The changes in the 34-hour reset (page 10) will affect nonunion drivers primarily, and will probably have no impact on Teamsters. This 2004 memo from the IBT Freight Division on the 34-hour reset is presumably still in force.