If both documents have been set up using the same set of named styles, then you can indeed import the definitions of these styles from one document/template to another. I seem to remember, though, that you can adjust the Compare settings to highlight formatting differences; don't know how to do this in 2007, but in 2010 – in case this helps point you in the right direction – it's Review tab > Compare > Compare two versions > More > Formatting.
HTH