This issue has been mitigated - users should no longer face any issues in accessing TFS projects.
We sincerely thank you for your patience and apologize for the inconvenience
Initial Update: 4/24/2014 1:00 PM UTC
Customers will experience some slowness on Codeplex when browsing projects, mostly TFS projects.
We're actively working on it, and will provide updates via this blog post.
The MSDN Service Delivery Team