Svn has a very useful concept, called externals.
The idea, in a nutshell, is that you include code from another subversion server (and repository) into your own subversioned project. Instead of simply copying the code into your project, you link to existing code. That way you simply update remote projects, when working from thirdparty development releases (that library the other team is developing on the sidetrack), and/or switch to new or stable versions when they are released.