Some of sourceforge's problems relate to just how many projects they host. For a while in
2003-2005, for example, the CVS servers were just not reliable. They've addressed that.
For a lot of projects, it's not a big deal to register a domain and host your own mailing
lists and defect trackers. Maybe that process was more difficult back when bugzilla was all
we had, but now we've got RT, TRAC, and a bunch of others. We've got SVN but also a ton of
distributed revision control tools.
Plus, as other comments have said, there's more than sf.net today.