Kinda...
SharePoint Portal Server 2003 uses WSS as it's underlying engine... you basically get a portal, robust search, my sites, and a profile database (I'm ~really~ dumbing it down).
You won't be able to "upgrade" a WSS site -> SPS. However the WSS site will still exist and run just fine. You could always write something that would move data from the WSS lists -> SPS lists, but the security doesn't work the same in a portal.
I'm not 100% sure about this, but I think you might be able to backup your WSS site (assuming it's a top-level WSS site) and restore it INTO the SPS site directory via stsadm.exe.
-AC
?
nntp://msnews.microsoft.com/microsoft.public.sharepoint.windowsservices/
Is it possible to do an in place upgrade from WSS to Sharepoint Portal
Server 2003?
Dan Foxley
[microsoft.public.sharepoint.windowsservices]