Unfortunately, SharePoint 2007 site templates
(.stp) can't be used as in SharePoint 2010. Hmm... Then what to do with the
custom SharePoint 2007 Site templates? Can't I use them in SharePoint 2010?
well
Solution packages (.wsp files) are the
supported method for creating sites that are based on a template in SharePoint
Server 2010. You can convert an .stp file to a .wsp file to continue to use the
template after upgrade.
