My number reason for not using CodePlex regularly is the choice of source control. I had heard of the SvnBridge a while ago, but had not had a chance to check out.

Tonight I wanted to grab some source from a couple CodePlex projects (StoreFront and MVC) and came across a really helpful post by Steven Harman which shows how to use a CodePlex hosted version of SvnBridge using the following URL Pattern.

https://your-project-here.svn.codeplex.com/svn

As Steven points out, if SVN is what you are after, I would still recommend Google code for new projects, but this will certainly make it easier for me to keep up to date on some of my favorite projects.