"The difference between wikis and sharepoint is that sharepoint sucks." - From a Discussion
"Instead of building one system that tries to do everything, build a system that is capable of integrating with everything. From an IT perspective, Enterprise 2.0 is about gaining network effects from various systems, rather than choosing one limited strategy that is supposed to be all things to all people." - What's wrong with Sharepoint?(which is quoting another source)
The only good thing about SharePoint is the money you can make by becoming an expert in it, but even then you'd have your conscience to worry about.