I filed the issue through http://connect.microsoft.com to acknowledge the problem and let everybody a chance to vote for it:
https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=230392
This is not a huge problem and it would take some time before VS leaks enough memory to actually notice the symptoms of the problem.
If you fill that fixing this bug is critical for you, please vote now!
Otherwise it would be fixed in the next release of VS.