We have just recently upgraded from 2008 software to the 2011 version of Civil3D. Our templates were created in 2008 can be used to create new drawings in 2011. All the styles are usable, plot and page setups, ambient settings, default layers, etc. are there. We haven't found a way to incorporate the new features of versions 2009-2011 into the styles, however, namely Mass Haul Lines, QTO, Hydraulic Grade Lines, and Energy Grade Lines. Is there anyway of incorporating these into the existing templates without recreating each one?
If not, is it planned for this process to be availavble in the future? Seems like it would be a good idea, considering more bells and whistles are added with each version.
Here is a good post it is for 2010 but the procedure is the same.
Check it out