What new can be said about SharePoint? SharePoint has a large and expanding range of capabilities across portal, collaboration, content management, enterprise search, business process management and business intelligence disciplines.
SharePoint 2010 promises numerous improvements that better equip it as an enterprise portal framework and as an environment for creating and delivering composite applications.
Built on a unified and consistent architecture, it has found its way into enterprises through a wide range of business and IT initiatives, not all of which are identified as portals.
It is the only large portal vendor with a multitenant, elastic cloud portal with a focus onoffice productivity and collaboration.
Using SharePoint as a portal framework means a long-term commitment to Microsoft's (news, site) agenda, with organizations employing SharePoint forced to invest in the .NET platform and the skills needed to support it.
It has also grown in many enterprises outside the scope of the reasons for its original deployment so there are also often governance concerns.
A pretty good summary of the strengths and weaknesses of SharePoint. In conclusion I would say if you are going Microsoft go SharePoint, otherwise try something else. Pretty simple decision as so many Enterprises are going Microsoft.