Will SNL upgrade to support SW2009/10 affect current 2008 clients?

Currently we have Solidworks 2008 deployed with 20 licenses available from an SNL Server w/ dongle.  I've seen the documentation stating that there is an upgrade for the license server that must be done to support the new version for testing in a new image but can't have the current version stop working.  Anybody done this already?SolidworksAdministration