Hello,
Even if you move to another server with same name and IP, the host id would 
have changed, this will cause the licences to expire ( you need to do a 
host transfer), unless the same server is renamed, in this case i belive 
licences will not expire, either way you can print out the registration 
report and send it to licening for update enablers, they are good about 
getting back to you quick.
In case of upgrade from 7.2.1 to 7.3, my best advise is waite, there are 
numeruous bugs that have been reported with the version and you are better 
off waiting till they are worked out, as far as testing you can just 
install a new copy on test system to check out the feature and new 
interface.
Hope that helps

To sign off this list, send email to listserv AT listserv.temple DOT edu and 
type "signoff networker" in the
body of the email. Please write to networker-request AT listserv.temple DOT edu 
if you have any problems
wit this list. You can access the archives at 
http://listserv.temple.edu/archives/networker.html or
via RSS at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER