So I know this is old news by now, but Linus Torvalds gave a talk last month on git, the version management system he wrote. He spends quite a lot of time bashing other SCM systems, particularly Perforce and Subversion. He writes off CVS entirely, which is perhaps warranted, but I thought his views on the other two products were way off. He doesn't really explain why he thinks that Perforce "should just go away", so I can't really comment on that, but curiously he does go on to complain about things that Perforce actually does rather well (like branching and merging). He also says clearly that he "is not an SCM person", so I guess that explains it.

For a much more informative and useful presentation on SCM, check out Laura Wingerd's (someone who is an SCM person) presentation at Google Talks: