My understanding is that DotNetNuke and IBM WebSphere are the only other
"portals" still gaining ground. All other competitors are loosing market
share.
It is my opinion nearly every shop running Office will be running
SharePoint to some extent within the next three years. Microsoft will
dominate this market because no one can easily compete with WSS. The
combination of free and integrated into Windows and Office is quite
compelling. portal will have competitors for specific features: Search,
SSO, ECM, etc.