As we approaching to TeamCity 7.1 release which is planned for the end of July, beginning of August, we concentrate our efforts on polishing new features and bugfixing. This EAP build does not have many new features besides some significant improvements in feature branches.
We've improved a lot in this area.
In previous EAP you could use * in branch specification, like this:
For TeamCity this rule means:
refs/heads/master, TeamCity will set
masterlabel to build